if 300 waves pass a point in one minute, the frequency is

Answer: 3

Explanation: i think

A boat can move at 30 km/h in still water, so to move 12 km upstream in a river flowing 6.0 km/h, it will take 20 minutes.

Water is referred to as still water when its motion is zero, or when it is still. Motionless water is defined as water that remains still, not flowing, and has no current, such as in rivers and streams. Therefore, a boat's relative speed on calm water is equal to 12 (a + b) km/hr. The stream is moving at a pace of 1/2 (a - b) km/hr.

Moving upstream, or against the flow of water, refers to a boat  going against the current. The distinction when speaking about water in rivers and streams is that upstream is in opposition to the water flow and in the direction of the water's original source (where the river originates).

To learn more about  still water  here

brainly.com/question/29248237

#SPJ4

The index of refraction of gas will be 1.008 units.

The number of wavelengths originally in the cylinder is m1 = 2L/λ when light is counted in both directions.

It transforms into m2 = 2L/λ/n gas.

= 2ngasL/λ​

As the cylinder is filled with gas,

If N is the number of bright fringes passing,

N = m2 - m1

= 2L/λ (ngas - 1) or,

The index of refraction of the gas is,

ngas =1 + Nλ/2L = 1+ (221)(502 x 10⁻⁹ m)/2(3.99 x 10⁻²)

= 1.008 units

To learn more about index of refraction refer to :

https://brainly.com/question/12469161

#SPJ4

No, it doesn't seem like the distribution is normal. A data set must (when graphed) follow a bell-shaped, symmetrical curve that is centered around the mean in order to be regarded as having a normal distribution.

The best way to determine whether a frequency distribution looks to have a normal distribution is to look at a histogram. Plot a histogram and study the bar shapes. The distribution is generally regularly distributed if the bars have the shape of a bell or a hill, as in the figure below. A theoretical continuous, symmetrical bell-shaped distribution function represents a normal frequency distribution. The bell curve's mean, mode, and median are all the same, and both of its tails are indefinitely long.

To learn more about frequency click here https://brainly.com/question/2140860

#SPJ4

complete question: Does the frequency distribution appear to have a normal distribution using a strict interpretation of the relevant criteria. Temperature ​(degrees​F) 35 - 39, 40 - 44, 45 - 49, 50 - 54, 55 - 59, 60 - 64, 65 - 9 frequency 3, 0, 6, 12, 8, 6, 1.

(a) No, the distribution does not appear to be normal.

(b) Yes, all the requirements are met.

(c) No, the frequencies do not decrease from the maximum frequency to a low frequency.

By performing a physics demonstration in front of the students. F is 9.79 x 108 newtons.

Given,

Mr. Gewanter weighs 60 kilograms (kg).

The weight of Martha is 55 kg.

d = 1.5 meters separates them.

The equation F = GMm/d2 newton determines the gravitational force between them.

changing the given values in the equation above

F = (6.673 x 1011 x 60 x 55)/1.52 = 9.79 x 108 newtons.

As a result, F = 9.79 x 108 newton is the gravitational pull Mr. Gewanter has on Martha.

A geostationary satellite travels in a circular path around the planet with a 36,000 km radius. The orbital period of a spy satellite will then be roughly (Re = 6400 km), orbiting a few hundred kilometers above the surface of the planet.

To know more about Newtons visit:

https://brainly.com/question/4128948

#SPJ1

Barometric column, barometer column, etc. mercury barometer: a device that uses a mercury column to measure the height of the column (in inches of mercury) to determine atmospheric pressure.

To learn more about Barometric column refer to:

https://brainly.com/question/24068374

#SPJ4

The magnitude of the electric field (in V/m) in the region between the plates is 20.35x10^5V/m.

Given the distance between the plates (d) = 1.4cm = 1.4x10^-2m

The potential difference across the plates is (V)  = 28.5kV = 28.5x10^3V

The electric field between two parallel conducting plates is dependent on the voltage or potential difference between the two plates as well as their separation from one another. The two charged parallel plates would carry their total charges since an electric insulator separates them. Because the two parallel charged plates are kept apart from one another, a homogenous electric field is created there.

According to Coulombs law E = V/d such that

E = 28.5x10^3V/1.4x10^-2m = 20.35x10^5V/m

Hence the required magnitude of the electric field is 20.35x10^5V/m

To learn more about electric field click here https://brainly.com/question/15800304

#SPJ4

What is Electric Field?

-- Electric field, an electric property associated with each point in space when charge is present in any form.

--The magnitude and direction of the electric field are expressed by the value of E, called electric field strength or electric field intensity or simply the electric field..

What is electric force ?

-- The repulsive or attractive interaction between any two charged bodies is called as electric force.

--  Similar to any force, its impact and effects on the given body are described by Newton's laws of motion.

-- The electric force is one of the various forces that act on objects.

Learn more about potential from https://brainly.com/question/49140

#spj4

The position of the point charge q can be placed such that the net electrostatic force is -1.857 m.

To find the position where the net electrostatic force on the charge q is zero, we need to apply Coulomb's Law. Coulomb's law states that the electrostatic force between two charges is proportional to the product of the charges and inversely proportional to the square of the charges. distance between them.

In this case, we have two charges Q1 and Q2 at known positions and we need to find the position of the third charge q such that the net force is zero.

By equating the force due to Q1 with the force due to Q2, we can solve for the position of q. Changing the sign of Q2 changes the direction of the force on q and changes the position of q.

To learn more about the electrostatic force at

https://brainly.com/question/9774180?referrer=searchResults

#SPJ4

The question is -

An electric point charge of Q1 = 7.43 nC is placed at the origin of the real axis. Another point charge of Q2 = 1.21 nC is placed at a position of p = 3.95 m on the real axis. At which position can a third point charge of q = -1.99 nC be placed so that the net electrostatic force on it is zero? Let the sign of Q2 be changed from positive to negative. At which position can the point charge q be placed now so that the net electrostatic force on it is zero?

Answer:

The mass has gained a height of 5 meters.

Explanation:

To calculate the height gained by a 2kg mass when 100J of gravitational energy is transferred to it, we can use the equation:Height (h) = Gravitational Potential Energy (GPE) / Weight (w)where GPE = mgh (mass x acceleration due to gravity x height)Therefore,h = (100 J) / (2 kg x 10 N/kg)h = 5 metersThe mass has gained a height of 5 meters.

The magnitude of the total electric field produced by the two objects at point p is 4*k*qa/0.25 m^2.

Electric field is a physical quantity used to describe the strength and direction of an electric force on a charged particle. It is a vector field, meaning that it has both a magnitude and a direction associated with it.

The total electric field at point p is the vector sum of the electric fields produced by object a and object b.
The electric field produced by each object at point p is given by:
E = k*q/r^2
where k is the Coulomb constant, q is the charge of the object, and r is the distance from the object to point p.
Therefore, the electric field produced by object a is:
Ea = k*qa/ra^2
And the electric field produced by object b is:
Eb = k*qb/rb^2
Since the charges of a and b are the same, we can use the same value for qa and qb. We can also use the same value for k.
Therefore, the total electric field at point p is:
E = Ea + Eb = k*qa/ra^2 + k*qb/rb^2
Substituting in the values given in the question:
E = k*qa/(0.250 m)^2 + k*qa/(0.500 m)^2
Simplifying gives:
E = 4*k*qa/0.25 m^2
Therefore, the magnitude of the total electric field produced by the two objects at point p is: E = 4*k*qa/0.25 m^2.

To learn more about electric field
https://brainly.com/question/14372859
#SPJ4

Despite being several streets away from the rail yard, the current downtown noise level is 70 dB. The people is given assurances by the mayor that they will see a difference.

The power carried via sound per unit area inside a perpendicular direction to the that region is known as sound intensity or acoustic intensity. A watt every square meter (W/m2) is indeed the SI unit for intensity, which also covers sound intensity.

The following equation can be used to calculate sound intensity: I=Δp22ρvw. p stands for pressure change or amplitude. is the density of the substance through which the sound is moving, and vw is the sound's measured speed. The more intense the acoustic waves oscillation, the bigger.

TO KNOW MORE ABOUT OSCILLATION VISIT:

https://brainly.in/question/14329100

#SPJ1

The car A will hit the car B during the reaction time of 0.5 seconds, and the distance the car will travel during the reaction time is 13.5 meters.

Reaction time is the time taken by the driver between seeing the scenario in front of his/her eye and the instant of applying the break. It is derived by the PIEV theory. The PIEV theory includes the time durations which drivers see, recognize, analyze and react to apply the brake for avoiding objects on the roads. The PIEV time on highway design engineering is taken as 2.5 seconds.

Given the speed of the car A is 27 m/s

Reaction time = 0.5 sec

Distance travelled, d = 27 × 0.5 = 13.5 meters

As the distance travelled by the car A is more than the distance between car A and car B, so the car will surely hit the car B.

To know more about reaction time, here

https://brainly.com/question/13693578

#SPJ4

The directions she gives are as follows: 1. Move 400 meters to the northwest. 3. The wealth is hidden there, 700 meters to the east-southeast.

Change inside an object's position in relation to a reference frame is known as displacement. For instance, a billiards ball moves of one spot to another when one player strikes it. It is alleged to have moved. A vector quantity with both size and direction is displacement.

The spacing between two specified points is represented by the one-dimensional quantity of displacement (symbolized as d or s), commonly known as length or distance. The meter serves as the standard displacement unit in the International Unit System (SI) (m).

To know more about directions visit:

https://brainly.com/question/13899230

#SPJ4

The tangential speed, v, must the bob have so that it moves in a horizontal circle with the string always maintaining an angle θ from the vertical is √mgLsinθtanθ.

Given the mass of bob = m

length of string = L

The angle the string of pendulum makes with cone =  θ

The tangential speed the bob moves = v

the vertical component of tension must support the weight of the bob which is represented as: Tcosθ = mg where g is acceleration due to gravity.

the horizontal component of tension must equal the centripetal force acting on the bob which is: Tsinθ = v^2/r where r is the radius of orbit.

However, we know that, r = Lsin(θ) then Tsinθ = v^2/Lsin(θ)

Then Tsinθ/Tcosθ = v^2/(mg x Lsin(θ))

tanθ = v^2/mgLsinθ

then v = √mgLsinθtanθ

Hence the tangential speed the bob moves with is √mgLsinθtanθ

To learn more about tension click here https://brainly.com/question/11348644

#SPJ4

The distance from the launch point to the plate is x = 0/v = 0/√3.5 x 10-15 = 0, meaning that the launch point must be at the same point as the plate.

Kinetic energy is the energy of motion. It is the energy associated with the movement of an object or particle, and is defined as the work needed to accelerate the object to its current velocity. Kinetic energy is a form of energy that is always associated with the movement of an object, regardless of its speed or direction. It is calculated by multiplying the mass of the object by the square of its velocity. Kinetic energy exists in both living and non-living objects, and is a key factor in the behavior of these objects.

The distance between the launch point and the plate can be determined using the formula for kinetic energy, which is E = ½mv². To solve for the distance, we rearrange the equation to v² = 2E/m and then plug in the given values: v² = 2(1.6 x 10-17)/(9.11 x 10-31) = 3.5 x 10-15. Then, using the equation x = vt, we solve for the distance x, where t is the time it takes for the electron to reach the plate. Since the electron needs to come to a complete stop, we set the velocity equal to zero. Thus, the distance from the launch point to the plate is x = 0/v = 0/√3.5 x 10-15 = 0, meaning that the launch point must be at the same point as the plate.

To know more about kinetic energy click-
https://brainly.com/question/25959744
#SPJ4

The amount of time taken in seconds for the bulb to transfer 300 J of energy into light energy is 37.5 seconds. (300 J / ( 12 W * 0.8))

The efficiency of a lightbulb is a measure of how much of the energy it consumes is converted into light energy, and how much is wasted as heat. A lightbulb with a higher efficiency will convert a greater proportion of the energy it consumes into light energy, and will therefore produce more light for the same amount of energy consumed. Conversely, a lightbulb with a lower efficiency will convert a smaller proportion of the energy it consumes into light energy, and will therefore produce less light for the same amount of energy consumed. The efficiency of a lightbulb is usually represented as a percentage, with 100% indicating that all the energy consumed is converted into light energy, and 0% indicating that none of the energy consumed is converted into light energy.

To know more about Light Energy visit: https://brainly.com/question/9444330

#SPJ4

The amount of time taken in seconds for the bulb to transfer 300 J of energy into light energy is 37.5 seconds.

Power = 12W

Efficiency = 80%

Energy = 300 J

Time taken =   (300 J / ( 12 W * 0.8))

                                  = 37.5 seconds

The efficiency of a lightbulb is a measure of how much of the energy it consumes is converted into light energy, and how much is wasted as heat. A lightbulb with a higher efficiency will convert a greater proportion of the energy it consumes into light energy, and will therefore produce more light for the same amount of energy consumed.

Conversely, a lightbulb with a lower efficiency will convert a smaller proportion of the energy it consumes into light energy, and will therefore produce less light for the same amount of energy consumed. The efficiency of a lightbulb is usually represented as a percentage, with 100% indicating that all the energy consumed is converted into light energy, and 0% indicating that none of the energy consumed is converted into light energy.

Learn more about Light Energy :

brainly.com/question/9444330

#SPJ4

The average velocity is 47.96 mi/h with which Jason can drive

on average.

Well, there are many ways to calculate the average velocity, but the most complete one would be the following.

With the equations of Uniform Rectelinear Movement we can obtain the distance Jason has driven. We will use the same equation for each step.

where x is the position,  is the initial position (which we can pick as zero to simplify), v is the velocity, t is time and  is the initial time (also picked as zero). In order to get the right answer we must use the same units, so we will change the minutes to hours, where 30 minutes are half an hour and 12 minutes are 0.2 hours

So, the distance will be Now that we have the partial distances, we use the formula for average velocity which is where  is the final position (the sum of the distances) and  is the total time Jason took.

Learn more about the distance and speed here:

https://brainly.com/question/12759408

#SPJ4

The total mechanical energy of the pendulum can be divided into potential energy and kinetic energy.

At the maximum height, the kinetic energy is 0 and all the energy is potential energy.

Therefore, the maximum height (h) can be calculated using the equation: h = (PE/m) / g = (75/5) / 10 = 1.5 m.

The rate of a pendulum at its maximum height is same to 0. At this factor, all the pendulum's overall mechanical electricity is in the shape of gravitational capacity strength. Because the pendulum swings down, the ability power is converted into kinetic electricity, achieving a maximum price at the lowest of its swing in which its pace is finest. On the most peak, the pendulum has no pace and consequently no kinetic energy, however its ability strength is at its most fee. For this reason, the speed of a pendulum at its most height is inversely proportional to its general mechanical strength.

To know more about Pendulum visit: https://brainly.com/question/29702798

#SPJ4

The maximum height reached by the pendulum is 15 meters.

Potential energy is a type of energy that an object possesses as a result of its position or configuration in a force field. It is energy stored in an object due to its height above a reference point, its state of compression or tension, or the arrangement of its constituent parts. Potential energy is relative to a reference point and is dependent on the strength of a particular force field. For example, the potential energy of an object on the edge of a cliff is related to the object's height above the ground, and the potential energy of a stretched spring is related to the amount it is stretched or compressed. The potential energy of an object can be converted into other forms of energy, such as kinetic energy, when the object is released or otherwise allowed to move in the force field.

To find the maximum height reached by a pendulum, we need to know the initial potential energy of the system, which is given by the equation:

PE = mgh

where m is the mass of the pendulum (5.0 kg), g is the acceleration due to gravity (10 m/s2), and h is the height.

Since the total mechanical energy of the system is given (75 J), we can set this equal to the initial potential energy:

75 J = 5.0 kg * 10 m/s2 * h

Solving for h, we find:

h = 75 J / (5.0 kg * 10 m/s2) = 15 m

So the maximum height reached by the pendulum is 15 meters.

To know more about energy visit:

https://brainly.com/question/28727910

#SPJ4

1.1.1: The force, which is 61.4 N and inclined at a 34.4° angle to the horizontal,

1.1.2: The resultant force is 30.8° inclined to the horizontal and is 66.9 N in magnitude.

How does vector addition work?

The process of adding vectors together to determine the resulting force is known as vector addition.

Vector addition is the theory that was applied in this question

The steps involved in adding vectors are as follows:

First, use the two provided vectors and the resulting vector to scale up a vector diagram.

Step 2: Apply the Pythagorean theorem to determine the magnitude of each vector.

Calculate each vector's angle with respect to the horizontal in step three.

4th step: Apply the  Use the law of cosines to find the magnitude of the resultant vector

Step 5: Use the law of sines to find the angle of the resultant vector with respect to the horizontal.

To learn more about vector addition refer :

https://brainly.com/question/25705666

#SPJ1

The statement which correctly describes the all of these given blood cell types is option C. They perform functions that air in maintaining homeostasis.

Any self-regulating mechanism called homeostasis helps biological systems to maintain stability while responding to environmental factors that are best for survival. If homeostasis is achieved, life goes on; if it is not, catastrophe or death result.

The stability obtained is actually a dynamic equilibrium, where circumstances are mostly uniform yet change is constant. All the bodily systems must be in a condition of equilibrium for the body to live and work properly.

When the body is in homeostasis, its levels of acid, blood pressure, blood sugar, electrolytes, energy, hormones, oxygen, proteins, and temperature are maintained at a normal level by being continually adjusted in response to changes both inside and outside the body. Hence, option C is correct.

Find more on  homeostasis:

https://brainly.com/question/13033059

#SPJ1

Answer:

671,3 Newtons

Explanation:

Fg=mass×g

The final kinetic energy of the electron is K2 = K1/4 since it is moving one-quarter as fast. The work done on the electron can be found using the equation W = K2 - K1 = K1/4 - K1 = -3/4K1. So, W=-3/4K1

The velocity of an object is directly proportional to its kinetic energy. As the velocity of an object increases, so does its kinetic energy. This relationship is described by the equation K = 1/2 * m * v^2, where K is the kinetic energy, m is the mass of the object and v is its velocity. This equation shows that the kinetic energy of an object is proportional to the square of its velocity. This means that if the velocity of an object is doubled, its kinetic energy will increase by a factor of four. Conversely, if the velocity of an object is halved, its kinetic energy will decrease by a factor of four.

To know more about Electron visit: https://brainly.com/question/1255220

#SPJ4

After a net amount of work W has been done on it, the electron is moving one-quarter as fast in the opposite direction W in terms of K1 =  W= -3/4K1

The final kinetic energy of the electron is K2 = K1/4 since it is moving one-quarter as fast.

The work done on the electron can be found using the equation

                                W = K2 - K1

                           = K1/4 - K1

                                 = -3/4K1.

So, W= -3/4K1

The velocity of an object is directly proportional to its kinetic energy. As the velocity of an object increases, so does its kinetic energy. This relationship is described by the equation K = 1/2 × m × v², where K is the kinetic energy, m is the mass of the object and v is its velocity.

This equation shows that the kinetic energy of an object is proportional to the square of its velocity. This means that if the velocity of an object is doubled, its kinetic energy will increase by a factor of four. Conversely, if the velocity of an object is halved, its kinetic energy will decrease by a factor of four.

Learn more about kinetic energy :

brainly.com/question/25959744

#SPJ4

A dropped ball is given if the ball hits the referee or another match official and goes into the goal, team possession changes, or a potential attack or a promising offensive begins.

The note of the following additional modifications to the dropped ball procedure The ball will be dropped for the goalie if play is stopped inside the penalty area. If the game is stopped outside of the penalty area, one player from the team that last touched the ball at the last touch will receive the ball. All other players from both teams must always be at least 4 metres or  4.5 yards away.

To learn more about Free kick :

https://brainly.com/question/30142857

#SPJ4

The force exerted by the biceps and the elbow is 239.9 N and 215.89 N respectively.

When we use only your forearms to lift an object, assume that your biceps are the main muscle that lifts your arm. Suppose the weight of the forearm he is 1.50 kg. If the biceps is attached to the forearm 2.50cm from the elbow, with the forearm parallel to the floor, flex the biceps to hold a 950g ball on the end of the elbow at a distance of 36.0cm from the elbow.

Against this background,

forearm mass = 1.50 kg

forearm length = 2.50 cm

The weight of the ball is 950 g.

36.0 cm ball spacing

Forearm strength needs to be calculated. Balance Elbow Using

Torque,

Fb x Db = Wf x Df/2 + Wball x Dball

Putting Value,

Fb x .025 = 1.5 x 9.8 x .36/2 + 0

95 x 9.8 x 0.36

Fb = 239.9 N

Now elbow force,

Fb = Fl + Wf + Wb

Fl = Fb - Wf - Wb

Putting value,

Fl = 239 .9 - (1.5 x 9.8 ) - (0.95×9.8)

Fl = 215.89 N.

Therefore the force on the elbow is 215.89 N.

To know more about work done, visit,

https://brainly.com/question/28199162

#SPJ4

No, it is not possible for you to travel from Earth to Andromeda in your lifetime.

Andromeda is a constellation located in the northern sky. It is named after the princess Andromeda in Greek mythology, who was chained to a rock as an offering to a sea monster.

To travel this distance in 20 years, you would need to travel at a speed of 0.99999999999999999c (where c is the speed of light). This is impossible, as nothing can travel faster than the speed of light.
The time it takes for the one-way trip to Andromeda as measured in the Earth-linked frame is 2.01 x 10^6 years. As measured in the rocket frame, this trip would take slightly longer due to time dilation effects caused by the high speed of the rocket. The rocket speed on Trip 1 as measured in the Earth-linked frame would be 0.00049975c, which is a decimal fraction of the speed of light.
For Trip 2, if we set the rocket time for the one-way trip to 20 years, then our speed would be 0.99999999999999999c as a decimal fraction of the speed of light. This is impossible, as nothing can travel faster than the speed of light.

To learn more about Andromeda
https://brainly.com/question/23844295
#SPJ4

Answer:

Option C.   10 m/s²

Explanation:

First we need to find the mass of the object.

We can use Newton's second law to evaluate the mass of the object.

Newton's second law says that the net force of is equal to the mass times it acceleration.

[tex]F_{net} =ma[/tex]

Lets solve for [tex]m[/tex].

Divide each side by [tex]a[/tex].

[tex]m=\frac{F_{net} }{a}[/tex]

We are given

[tex]F_{net} =45\\a=5[/tex]

Lets evaluate [tex]m[/tex].

[tex]m=\frac{45}{5}[/tex]

[tex]m=9[/tex]

Now we can find the object's acceleration if the force doubles.

[tex]F_{net} =ma[/tex]

Lets solve for [tex]a[/tex].

Divide each side by [tex]m[/tex].

[tex]a=\frac{F_{net} }{m}[/tex]

Doubling the force of 45 N leaves us with a force of 90 N.

[tex]a=\frac{90}{9}[/tex]

[tex]a=10[/tex]

We can see that the object's acceleration is directly proportional to the net force and inversely proportional to the object's mass.

The moment (in KN-m) produced by the force about an axis in the direction of i+j+k (from the origin) if a force of 5 KN to a wall is 5 (cos θ + sin θ)

That is called torque when we calculate its moment of force. Torque is а meаsure of the force thаt cаn cаuse аn object to rotаte аbout аn аxis. Just аs force is whаt cаuses аn object to аccelerаte in lineаr kinemаtics, torque is whаt cаuses аn object to аcquire аngulаr аccelerаtion.

We are given:

Force = 5 KN

Horizontal Component i = [tex]F_{x}[/tex] = 5 cos θ

Vertical Component j =  [tex]F_{y}[/tex] = 5 sin θ

x component of the moment (in kN-m):  

M = [tex]F_{x}[/tex] × d

= 5 cos θ × d (kN - m)

d is the distance of the force form origin.

Force about an axis in the direction of i + j + k:

=  [tex]F_{x}[/tex] +  [tex]F_{y}[/tex] +  [tex]F_{z}[/tex]

= 5 cos θ + 5 sin θ + 0

= 5 (cos θ + sin θ)

Your question is incomplete, but most probably your full question can be seen in the Attachment.

For more information about torque refers to the link:

https://brainly.com/question/29024338

#SPJ4

Your average velocity for the journey has been 94.57 km/h.

The average velocity of an object is the ratio of total displacement to the total time of motion of an object.

V = ( total displacement ) / ( total time )

The total displacement of your journey is calculated as;

x = 485 km - 154 km

x = 331 km

The total time of the motion is calculated as;

t = 4:30 - 1:00 = 3:30 = 3.5 hours

v = x / t

v = ( 331 km ) / ( 3.5 hr )

v = 94.57 km/h

Learn more about average velocity here: https://brainly.com/question/24445340

#SPJ1

The work done in case a) is positive, in case b) is negative and in case c) is positive.

Work is said to be done when the displacement is occur in the direction of the applied force.  

W = F×d×cosθ

Where F is the force, d is the displacement and θ is the angle between the displacement and the direction of the force.

In case a) as the work is done against the direction of the gravity so the work is positive. In case b) the weight of the buckets acts in downwards direction, that is the direction of the acceleration due to gravity. So the work is negative. In case c) the bucket were lowered, it means the displacement is in the direction of the applied force. Hence the work done is positive.

To know more about force, here

https://brainly.com/question/13191643

#SPJ4