Answer:
The work done by gravity is 784 J.
Explanation:
Given:
Mass of the block is, 
Height to which it is raised is, 
Acceleration due to gravity is, 
Now, work done by gravity is equal to the product of force of gravity and the distance moved in the direction of gravity. So,

Force of gravity is given as the product of mass and acceleration due to gravity.
. Now,

Therefore, the work done by gravity is 784 J.
I think the answer would be 1 watt but i'm not sure
Answer:
P = 0.25 W
Explanation:
Given that,
The emf of the battry, E = 2 V
The resistance of a bulb, R = 16 ohms
We need to find the power delivered to the bulb. We know that, the formula for the power delivered is given by :

So, 0.25 W power is delivered to the bulb.
The statement that can be used to answer this question is:
"If the cylinder is brought higher then, its temperature when brought down becomes higher because a greater amount of potential energy is converted to thermal energy."
The potential energy is converted to thermal energy when the object is released the velocity becomes higher because of the acceleration due to gravity.
Well it seems like this problem gives you what you need. You said the car was going 4m/s and then accelerated to 60m/s... so 4m/s would be your answer for the initial velocity