Answer:
a
all the molecules or atoms in motion has kinetic energy
I’m not sure what you are asking
Answer: Power is 200 W
Explanation: Power P = work done / time used.
P = W/t = mgh/t = 154 kg · 9.81 m/s²· 4 m / 30 s = 201 W
The normal force acting on the object is 500 N in the upward direction
<u>Explanation:</u>
As George is applying a downward force, the normal force will be in the upward direction. The normal force will be exerted due to the acceleration due to gravity exerted on the object.
So, as per Newton's second law, the normal force acting on the object can be measured by the product of mass of the object and the acceleration due to gravity acting on the object.
But as the acceleration due to gravity is a downward acting acceleration and the normal force is a upward acting force, so the acceleration will be having a negative sign in the formula.

Here, acceleration due to gravity g = -10 m/s² and mass is given as 50 kg, then
Normal force = 50 × (-10) = -500 N
So, the normal force acting on the object is 500 N in the upward direction.
The answer to your question is 343 m/s