A440 kg roller coaster car is going 26 m/s when it reaches the lowest point on the track. if the car started from rest at the top of a hill, how much higher was that point on the track than the lowest point? (use g = 9.80 m/s2, and ignore friction.)

choices are these:
17 m23 m34 m69 m

If the area of a square has increased by a factor of 16, by how much has each side increased?

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.

What ia the energy of an object because of its potential and kinetic energies