A heat engine cannot have a thermal efficiency of 100% For all reversible processes, the second-law efficiency is 100%. The second-law efficiency of a heat engine cannot be greater than its thermal efficiency. The second-law efficiency of a process is 100% if no entropy is generated during that process
A rock excerts a pressure of 20 N/cm^2 on the ground. what does 20N/cm^2 mean?
A force of __________ acts on each _________ of area
Answer:
A force of 20N acts on each cm^2 of area
Mercury’s natural state is where the atoms are close to each other but are still free to pass by each other. In which state(s) could mercury naturally exist?
Answer:
Mercury's natural state is where the atoms are close to each other but are still free to pass by each other. In which state(s) could mercury naturally exist?
Liquid is the answer
Explanation:
At the exact same instant that a
ball is thrown horizontally (in a
projectile) another identical ball
is dropped straight down from
the same height. Which ball hits
the ground first?
Answer:
The ball being thrown straight down.
Explanation:
The downforce and gravitational pull of the ball going down will give it
a higher velocity compared to the one trown horizontially it will take some time for it to catch downforce speed and reach the same velocity.
1. A stone is thrown vertically upward with velocity of 15 m/s at the same time, 10 m vertically above a second stone is allowed to fall. After what time and at what height do they collide (take g = 10 ms^-2)
Let the ball at the ground be A and that at the top be B.
Assume that you see the motion of A while sitting at B.
You(B) are obviously at rest w.r.t. yourselves. However you(B) and A have the same acceleration in the same direction. Thus acceleration of A w.r.t. you(B) is 0.
Thus, to you, it will appear as if A is travelling towards you with an uniform speed of 20m/s.
Dividing the distance 20m with that speed, we get that A reaches you(B) in 1s.
Now, you have considered these motions and time by assuming you were stationed at B. However, the time taken for A to meet B shouldn't be dependent on which reference frame you assume. Thus, time taken for A and B to collide is 1s.
Since B falls freely, he covers a distance of 1/2(g)(1²)=5 (assuming g = 10m/s²)
Thus, they meet at a height of (20–5)m = 15m from the ground.
this planet has a very toxic atmosphere that traps heat, making it the hottest planet in the solar system.
Answer:
Venus
Explanation:
basic 2nd grade smarts "no offense"
You are walking back toward the back of a bus that is moving forward with a constant velocity. Describe your motion relative to the bus and relative to a point on the ground.
Answer: Relative to the bus, you are stationary. Relative to a point on the ground, you are walking forward with velocity equal to the velocity of the bus.
As a person walks toward the back of a bus, they are walking towards a stationary object according to their own perspective. However, from an outside perspective, the bus is moving forward with a constant velocity and so relative to that point in motion, you are actually walking backwards with respect to it. This difference in motion means you would not be able have the same experience as the person on the bus when getting off because when you get off you would stop while they continue going forward. The last sentence could be considered a footnote because it only applies if this was an actual situation rather than just an analogy question in a physics test.
Relative to the bus, you move at walking speed. The motion relative to the ground is in the direction same as the bus and equal to the difference between the speed of the bus and walking speed.
What is relative motion?When an object has a certain velocity, then this velocity is w.r.t. some frame that is called the reference frame. When we measure the velocity of an object, the ground or the earth is taken as the reference frame.
The motion of an object observed by the observer depends on the frame of the observer and this type of motion is known as relative motion.
For example, if you are traveling in a train and the train is moving at a speed of 80 km/hr, then your speed according to another passenger sitting on the same train is equal to zero.
Similarly, if you are walking toward the back of a bus, then your motion relative to the bus is walking speed. Relative to the ground, it is the difference between the speed of the bus and walking speed.
Learn more about relative motion, here:
https://brainly.com/question/776045
#SPJ2
A bowling ball and a ping-pong ball are each tied to a string and hung from the ceiling. The distance from the ceiling to the CM of each object is the same. Which object would have a longer period of motion if they were set swinging
HELPPPPPPPPPPPPPPPPPPP
Answer:
directly proportional
Explanation:
Two cars a and b are moving along a straight road in the same direction with velocities of 25km/h and 40km/h . Find the velocity of car b relative to car a
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
Which will be different on the moon than it is on Earth?
weight
mass
Answer:
Below
Explanation:
On the moon, an objects weight will be different than it is on earth. This is because we cannot change the mass of an object, the mass of an object is the measure of matter an object has. However the weight is depended on the gravitational pull of whatever planet you are on. In this case, weight will be lighter on the moon than it is on earth because the moon's gravitational pull is 1.62 m/s^2 while earths is around 9.8 m/s^2.
Hope that helps!
A. Read these sentences carefully. Choose the correct form of adjectives.
1. Solomon is the
king of all.
a wise
b. wiser
c. wisest
2. Yogurt is
than candies.
a delicious b. more delicious c. most delicious
3. Mayon Volcano is the
volcano for me.
a most majestic b. more majestic
c. majestic
4 My father is an
man
a industrious b. more industrious c. most industrious
5. I was the
when my friend graduated with honors.
a happy b. happier
c. happiest
Answer:
1. wisest
2. more delicious
3. majestic (not sure about this one)
4. industrious
5. happiest
Which is the BEST example of physics in the body?
A. a single beat of the heart
B. how the circulatory system works
с. balance when the body is standing still
D. the movement of an arm throwing a ball
The best example of physics in the body is the movement of an arm throwing a ball. The correct option is D.
What is physics?Physics is the branch of science that studies the structure of matter and how the universe's fundamental constituents interact.
It investigates objects ranging from the very small to the entire universe using quantum mechanics and general relativity.
Physics is the natural science that investigates matter, its fundamental constituents, its motion and behavior in space and time, as well as the related entities of energy and force.
Physics is one of the most fundamental scientific disciplines, with the primary goal of understanding how the universe functions.
The movement of an arm throwing a ball is the best example of physics in the body.
Thus, the correct option is D.
For more details regarding physics, visit:
https://brainly.com/question/28600368
#SPJ2
A car goes from 60 m/s to 75 m/s in 10 seconds.calculate the car’s acceleration?
Explanation:
Uhhhh here is an example
a=vt. =27 m/s10 s. =2.7 m/s2.
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Acceleration of the car is ~
[tex] \boxed{1.5 \: \: m/s}[/tex]
[tex] \large \boxed{ \mathfrak{Step\:\: By\:\:Step\:\:Explanation}}[/tex]
We know that,
Acceleration = rate of change in velocity ~
that is ~
[tex]a = \dfrac{v - u}{t} [/tex]where,
v = final velocityu = initial velocity t = time taken ~now, let's solve ~
[tex]a = \dfrac{75 - 60}{10} [/tex][tex]a = \dfrac{15}{10} [/tex][tex]a = 1.5 \: \: m/s[/tex]
How much potential energy did the the milkshake have after it fell off of the counter, just before it hit the ground (at the bottom)? Make sure to write the correct units with
your answer!
Answer:
The formula for potential energy depends on the force acting on the two objects. For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters.
if 20 boys can sweep the school compound in 8 minutes, how many boys can sweep it in 10minutes
Answer:
So this is just a ratio/proportion problem
so lets say its in boys:minutes
so in the first scenario
20:8
and we want to find
x:10
So proportion really
20/8=x/10
cross multiply
25
25 boys can sweep it in 10 minutes
Block 1, of mass m1, moves across a frictionless surface with speed ui. It collides elastically with block 2, of mass m2, which is at rest (vi=0). (Figure 1)After the collision, block 1 moves with speed uf, while block 2 moves with speed vf. Assume that m1>m2, so that after the collision, the two objects move off in the direction of the first object before the collision. What is the final speed vf of block 2?
The conservation of the momentum allows to find the velocity of the second body after the elastic collision is:
[tex]v_f = \frac{2u_o}{1- \frac{m_2}{m_1} }[/tex]
the momentum is defined by the product of the mass and the velocity of the body.
p = mv
The bold letters indicate vectors, p is the moment, m the mass and v the velocity of the body.
If the system is isolated, the forces during the collision are internal and the it is conserved. Let's find the momentum is two instants.
Initial instant. Before crash.
p₀ = m₁ u₀ + 0
Final moment. After crash.
[tex]p_f = m_1 u_f + m_2 v_f[/tex]
The momentum is preserved.
p₀ = [tex]p_f[/tex]
[tex]m_1 u_o = m_1 u_f + m_2 v_f[/tex]
Since the collision is elastic, the kinetic energy is conserved.
K₀ = [tex]K_f[/tex]
½ m₁ u₀² = ½ m₁ [tex]u_f^2[/tex] + ½ m₂ [tex]v_f^2[/tex]
Let's write our system of equations.
[tex]m_1 u_o = m_1 u_f + m_2 v_f \\m_1 u_o^2 = m_1 u_f^2 + m_2 v_f^2[/tex]
Let's solve
[tex]u_f = u_o - \frac{m_2}{m_2} \ v_f \\u_f^2 = u_o^2 - \frac{m_2}{m_1} \ v_f^2[/tex]
[tex]( u_o - \frac{m_2}{m_1} v_f)^2 = u_o - \frac{m_2}{m_1} \ v_f^2 \\u_o^2 - 2 \frac{m_2}{m_1} \ u_o v_f + (\frac{m_2}{m_1} )^2 v_f^2 = u_o^2 - \frac{m_2 }{m_1} \ v_f^2[/tex]
[tex]2 \frac{m_2}{m_1} \ u_o = \frac{m_2}{m_1} v_f \ ( 1 - \frac{m_2}{m_1}) \\v_f = \frac{2u_o}{1-\frac{m_2}{m_1} }[/tex]
In conclusion, using the conservation of momentum, we can find the velocity of the second body after the elastic collision is:
[tex]v_f = \frac{2u_o}{1-\frac{m_2}{m_1} }[/tex]
Learn more here: brainly.com/question/8351094
waht is pascal law?
Answer:
P=\frac{F}{A}
P = pressure
{F} = force
{A} = area
Explanation:
8.
Linda thinks that her home is dirty and she will become
contaminated if she does not clean her kitchen. This daily cleaning takes hours to complete. Her hands
are rubbed raw, she has not been able to maintain friendships, and she is struggling to keep up with
work.
Answer:
she just have to maintain her daily work routin to kepp up with work .she can use glovs than her hand will be protected .and for mantain friendship she have to franky with other and allways talk to you'r friends no matter how bg you are talking with friends can be verry helpfull
Two cars A and B are moving along a straight road in the OPPOSITE direction with velocities of 25 km/h and 40 km/h, respectively. Find the velocity of car B relative to car
Answer:
65km/h
Explanation:
Here,
Relative velocity of car moving in different directions with different velocities =Va + Vb
=25+40
=65 km/h
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
what noncontact forces act on an object that are balanced
Answer:
I can give you a list of noncontact forces off of my head, if that is what you need.
Explanation:
First, gravity. It acts everywhere and pulls down every object that is in the air towards the ground, unless they have an equal and opposite force that counters it.
Second, wind. I don't think this will count because wind is a physical thing, but it can be used in the same way as we did with gravity. If the force counteracting it is larger, equal, and opposite of the force it is countering, then it will move forward, through the wind.
Suppose measure the mass of an orange. Then you peel the orange and separate out the slices. If you measure the orange peel and all the slices, will that mass equal the mass of the whole orange?
yes
no
The mass of the orange after it has been cut into pieces will still remain the same as the mass of the whole orange.
Let us recall that the law of conservation of mass states that, mass can neither be created nor destroyed but is converted from one form to another. In accordance with this law of conservation of mass. The mass of the orange must remain the same after it has been cut in pieces.
Hence, If the mass of an orange is measured after it has been cut into pieces, the mass of the orange after it has been cut into pieces will still remain the same as the mass of the whole orange.
Learn more: https://brainly.com/question/865531
The spark plugs are threaded into the top of each cylinder and provide a place for the spark to jump within the ________.
Answer:
"the spark plug gap"
The plug provides a gap between the input voltage and the ground supplied by the car chassis.
Compare and contrast instantaneous and average speed.
Answer:
instantaneous velocity is a velocity covered at an instant while average velocity is the change in distance/ the change in time taken
PLz help--- What's happening here?
This object is not moving
This object is not changing speeds.
This object is changing speeds; it's getting faster.
This object is changing speeds; it's getting slower.
Answer:
getting faster
Explanation:
the curve gets more steeper, and steeper line shows more distance for less time, meaning faster.
Image credit: The Hubble Heritage Team (AURASTSCI/NASA)
To which category does galaxy #2 belong? Why does it belong in this category?
WRITER
Can i ask u a question
how to do the next ques for moreBrainliest me please
Fuses of ________________________
a. same kind are used for different purposes
b. different kind are used for different purposes
c. both of the above are correct
d. none of these
Answer:
C
Explanation:
fuses of same kind can be used for different things, and of different kinds could be used for different things as well.
I need to know how to draw the diagram of the last two questions
Answer
In the parallel circuit, you have to position the switch on only one of the loops.
Look at the diagram shown below. The reading on ammeter 1 is 0.15 A. What will the reading on ammeter 2 be
There's no way to tell, without knowing the resistance of either X-1 or X-2, or the reading on A3.
A block with initial velocity of 3 m/s slides 9 m across a rough horizontal surface before coming to rest. What is the coefficient of kinetic
friction?
The coefficient of kinetic friction between the block and the horizontal surface is 0.051.
The given parameters;
initial velocity, u = 3 m/sdistance traveled by the block, s = 9 mThe acceleration of the block is calculated as follows;
[tex]v^2 = u^2 + 2(-a)s\\\\v^2 = u^2 - 2as\\\\a = \frac{u^2 - v^2}{2s} \\\\a = \frac{3^2 - 0^2}{2\times 9} \\\\a =0.5 \ m/s^2[/tex]
The coefficient of kinetic friction between the block and the horizontal surface is calculated as follows;
[tex]\mu_k mg = ma\\\\\mu_k = \frac{a}{g} \\\\\mu_k = \frac{0.5}{9.8} \\\\\mu_k = 0.051[/tex]
Learn more here:https://brainly.com/question/19454558
3. What happens if an object has a negative acceleration?
Answer:
They will go backwards?
Explanation:
If positive they go forward but is negative they go backwards.