The supplied energy is used for phase transition, not molecule kinetic energy.
Example: ice cannot be heated above 0Cº when it is being melted. Heat is consumed for phase change during its transition from solid to liquid. Only after all ice has melted, the temperature will rise until the next phase transition - vapor.
Since the car speeds up at a constant rate, we can use the kinematic equation for distance (assuming that the initial position is x=0, and choosing t₀ =0), as follows:
Since the car starts from rest, v₀ =0.
We know the value of t = 5 sec., but we need to find the value of a.
Applying the definition of acceleration, as the rate of change of velocity with respect to time, and remembering that v₀ = 0 and t₀ =0, we can solve for a, as follows:
Replacing a and t in (1):
Now, if the truck slows down at a constant rate also, we can use (1) again, noting that v₀ is not equal to zero anymore.
Since we have the values of vf (it's zero because the truck stops), v₀, and t, we can find the new value of a, as follows:
Replacing v₀, at and t in (1), we have:
Therefore, as the truck travels twice as far as the car, the right answer is a).
19116 being the distance from the centre of the earth to the point you want to check in metres. So after all that you get G = 1.0888m/second squared. Hope that helps you/ you should be able to pop in any height you want.