Answer:
I disagree
Explanation:
I think the students claim is wrong because according to Newton's First Law an object that is in motion stays in motion unless acted upon by an unbalanced force. Which makes the students claim wrong because a object doesn't require another force to keep it moving.
Answer:
A. It is zero.
Explanation:
D Later in the day, more power is developed in lifting each box. 12 A manometer is used to indicate the pressure in a steel vessel, as shown in the diagram. What value does the liquid manometer give for the pressure in the vessel? It is zero
Answer: 211.059 m
Explanation:
We have the following data:
The angle at which the ball leaves the bat
The initial velocity of the ball
The acceleration due gravity
We need to find how far (horizontally) the ball travels in the air: 
Firstly we need to know this velocity has two components:
<u>Horizontally:</u>
(1)
(2)
<u>Vertically:</u>
(3)
(4)
On the other hand, when we talk about parabolic movement (as in this situation) the ball reaches its maximum height just in the middle of this parabola, when 
and the time 
is half the time it takes the complete parabolic path.
So, if we use the following equation, we will find :
(5)
Isolating :
(6)
(7)
(8)
Now that we have the time it takes to the ball to travel half of is path, we can find the total time 
it takes the complete parabolic path, which is twice :
(9)
With this result in mind, we can finally calculate how far the ball travels in the air:
(10)
Substituting (2) and (9) in (10):
(11)
Finally:
Answer:
Explanation:
Potential energy on the surface of the earth
= - GMm/ R
Potential at height h
= - GMm/ (R+h)
Potential difference
= GMm/ R - GMm/ (R+h)
= GMm ( 1/R - 1/ R+h )
= GMmh / R (R +h)
This will be the energy needed to launch an object from the surface of Earth to a height h above the surface.
Extra energy is needed to get the same object into orbit at height h
= Kinetic energy of the orbiting object at height h
= 1/2 x potential energy at height h
= 1/2 x GMm / ( R + h)
