Science Questions :)

Answer:

1

Explanation:

because when we use v=u+at we derived v-u÷t

Answer:

it is correct

Explanation:

Though no rounded numbers can be defined as accurate, if we were going by people's discovery, and research, we can define that the number, g = 9.8m/s^2, is accurate

Answer:

Work done = Fs

Explanation:

(i) W = Fxs

= 84N x0.25m

= 21 Joules

(ii) Ek = 1/2mv^2

71 = 1/2×27×v^2

71×2/27 = v^2

v = 23m/s

The work done by this force is 21 Joule.

Energy transferred by the force is 21 Joule.

The boy's momentum changes periodically, that is,  in both size and direction.

An external force is an agent that has the ability to change the resting or moving condition of a body. It has a direction and a magnitude. So, it is  a vector quantity. Newton is the SI unit of force (N).

(i) Given parameter:

Steady force applied by his brother, F = 84 N.

Displacement, d = 0.25 m.

The work done by this force, W = F.d = 84×0.25 = 21 Joule.

(ii) Amount of work done is transferred by this force as an energy. So, amount of energy transferred by the force is 21 Joule.

(iii) Given parameter:

Mass of the child, m= 27 kg.

Kinetic energy, E = 71 J.

Let, velocity of the child = v, then kinetic energy is,

E = 1/2 × mv²

⇒ v = √(2E/m)

= √(2×71/27)

= 2.3 m/s.

Hence, the velocity of the boy is 2.3 m/s. (proved).

(iv) During swing, his velocity changes periodically. That's why, his momentum changes periodically, that is,  in both size and direction.

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Answer:

80kg

Explanation:

A = Fm

0.5 = 40m

m = 40/0.5

m = 80kg

guaranteeing freedom of speech, press, assembly, and exercise of religion

Answer:

a. climbing up a cliff

Explanation:

Explanation:

acceleration remains constant when velocity does not increase or decrease

Answer:

.............................

Answer:

transverse wave, motion in which all points on a wave oscillate along paths at right angles to the direction of the wave's advance. Surface ripples on water, seismic S (secondary) waves, and electromagnetic (e.g., radio and light) waves are examples of transverse waves.

Answer:

Journey A average speed is 19.86 meters per second

Journey B average speed is 13.68 meters per second

Explanation:

The average speed is defined as the distance divided by the time, so that's what we have to do. But first, let's convert the time in seconds and the distance in meters, because we have to answer in meters per second:

Journey A:

2 hours = 120 minutes. Each minute have 60 seconds, so 120•60= 7200 seconds.

143 km = 143000 meters

143000/7200 = 19.86 m/s

Journey B:

3 hours = 180 minutes + 15 minutes = 195 minutes

195•60 = 11700 seconds

160 km = 160000 meters

160000/11700 = 13.68 m/s

Answer:

Cretacious-Tertiary

Explanation:

I hope this helps!

Answer:

R = V/I

Explanation:

Example:

V = IR

R = V/I

If we were to use V = 120 and I = 0.25

R = 120/0.25

R = 480 Ohms

Your resistence would equal Ohms

Answer:

what is the average speed of the toy car during the two trials to the nearest tenth of m/s

wait nvm the answer is B

Explanation:

CARRY ON LEARNING

Answer:

Molar mass of NH3=14+3=17g

[tex]mole = \frac{given \: mass}{molar \: mass} \\ mole = \frac{28}{17} \\ mole = 1.65[/tex]

BRAINLIST

Answer:

True

Explanation:

Since acceleration is inversely proportional to mass, decreasing mass will make the object lighter, and thus easier to speed up. So acceleration increases as mass decreases and vice versa

Answer: TRUE                                                                        Explanation:Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Answer:

the bird has 550J of potential energy

Explanation:

PEtotal=PE+KE

1000J=PE+450J

subtracting the kinetic energy from the total we get:

1000J-450J=PE

550J=PE

The magnitude of the acceleration of the block is 3.5 [tex]\bold{m/s^2.}[/tex]

The correct option is (C) 3.5 [tex]\bold{m/s^2.}[/tex]

Acceleration is the rate of change of velocity with time.

By Newton’s Second law

This law establishes the relationship between the net applied force on an object with the resultant acceleration. For a constant magnitude of force, the more is the mass of the object, the lesser will be its acceleration.

Given,

The mass of the block is 2.0 kg.

The force in the horizontal direction on the block is [tex]\bold{4.0 N + 4.0 N \cos 40{}^\circ.}[/tex]

a is the acceleration in the horizontal direction.

The acceleration for the block can be determined using Newton’s Second law,

[tex]\begin{aligned} \Sigma F&=ma \\ F+F\cos 40{}^\circ &=ma \\ a&=\frac{F\left( 1+\cos 40{}^\circ \right)}{m} \\ &=\frac{4.0\text{ N}\left( 1.766 \right)}{2.0\text{ kg}} \\ &=3.5\text{ m/}{{\text{s}}^{2}} \end{aligned}[/tex]

Thus, the acceleration is 3.5 [tex]\bold{m/s^2.}[/tex]

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Answer:

I think it would be c, crashing into another car

Please find attached photograph for your answer.

Hope it helps.

Do comment if you have any query.

Answer:

zsjgbjidasngwhugbhwuabvhuvbwhuebewghvwev

Explanation:

11111111111111111111111111111111111111111111111111111

hplhevsdvakxjb1zonsvaka shdv

Answer:

Massm=2.5kg

Massm=2.5kgGravitational potential energy is the work done against force of gravity is stored in the body at a height h .

Massm=2.5kgGravitational potential energy is the work done against force of gravity is stored in the body at a height h .P.E.=U=mgh

Massm=2.5kgGravitational potential energy is the work done against force of gravity is stored in the body at a height h .P.E.=U=mghU=2.5×10×15

Massm=2.5kgGravitational potential energy is the work done against force of gravity is stored in the body at a height h .P.E.=U=mghU=2.5×10×15U=25/10×10×=375j

Answer:

it increased by 29 sorry hope this helps

Answer:b

Explanation:

Answer: One rocket has more fuel than the other

Two rockets are being tested. Both rockets have the same mass. One rocket accelerates at a higher rate than another rocket. One rocket has more fuel than the other

A rocket is a special type of jet-propulsion device which carry either solid or liquid propellants and it provide both the fuel and oxidizer needed for combustion.

The rocket is commonly applied to various vehicles, including firework skyrockets, guided missiles, and launch vehicles applied in spaceflight..

The rocket is different from the turbojet and other “air-breathing” engines exhaust jet consists of the gaseous combustion products of “propellants” carried on board.

The  physical principle involved in rocket propulsion was  derived by Sir Isaac Newton. According to third law of motion, the rocket experiences an increase in momentum proportional to the momentum carried away in the exhaust,

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Answer: natural

Explanation:

Answer:

natural i just copy tha answer in there i just explain it(づ￣ 3￣)づ

Explanation:

The meaning of the term “Pursuit of Happiness.” In the Declaration of Independence, Thomas Jefferson announced that every human being has “certain unalienable rights,” among which are those to “life, liberty, and the pursuit of happiness.” What did he mean by “the pursuit of happiness”?

Answer:

Theta = 26.93°

R = 0.38m

Explanation:

Theta = cos^-1(0.74m/0.83m)

Theta = 26.93°

R = sqrt(0.83²-0.74²)

R = 0.38m