A 1500 Kg car is stalled on the railroad tracks and is hit by a 25,000 kg train, the car and the train move forward together after the collision at 25 m/s. The engineer said he was travelling at under 30m/s. Was he telling the truth? The speed of the train before the collision was m/s​

How would doubling the made of an object change the objects potential energy

Aplayground merry-go-round has a radius of 4.6 m and a moment of inertia of 200 kg-m2 and turns with negligible friction about a vertical axle through its center. a child applies a 26.0 n force tangentially to the edge of the merry-go-round for 15.0 seconds. if the merry-go-round is initially at rest, how much work did the child do on the merry-go-round?

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of