Answer:
1) U-> K +W
2) K -> W
Explanation:
In this exercise, care must be taken as they indicate that the friction force (rubbing) is not negligible.
1 part at the top of the hill the car has gravitational potential energy, which is transformed in a part into kinetic energy and another part into heat by the work of the friction force that opposes the movement.
2 part when the other hill rises it loses kinetic energy that is transformed into gravitational potential energy and part in heat due to the work of the friction force on this hill.
3rd part in the last descent all the gravitational potential energy is transformed into kinetic energy and the application of the brakes is transformed into heat due to the negative lock of the friction force and filled with gasoline that has chemical energy that can be transformed in the engine.
Kg m/s : kilograms meters per second
The acceleration of gravity is
9.8 m/s^2 down.
When an object falls out of a hand, its speed after 1.8s is
(9.8)x(1.8) = 17.6 m/s down.
It doesn't matter what it is, how much it weighs, or how high it was dropped from.
If it's more than 17.6 m/s, then this happened on a different, bigger planet.
If it's less than 17.6 m/s, then it must have hit something on the way down, like some air or something.
a = ( V2 - V1)/( t2 - t1)
3.2 = ( 23.5m/s - 15.2m/s)/(t - 0)
3.2m/s = 8.3/t
t(3.2) = 8.3
t = 8.3/3.2
t = 2.59 seconds
