A 75 kg person stands on top of a 25-meter-high building. Calculate their potential energy relative to the ground. A 2000 kg truck traveling at 10 m/s collides with a stationary 1000 kg car. After the collision, the truck moves at 6 m/s. Calculate the velocity of the car after the collision. A 500-gram cart is rolling down a ramp with an initial velocity of 2 m/s. If the ramp is 3 meters high and the cart experiences 50% energy loss due to friction, calculate the cart's final velocity at the bottom of the ramp.