Why is a pencil bent when bent in water

Arock is dropped from a cliff and reaches the ground in 2.70s. at the same time another rock is thrown horizontally from the same height with initial x velocity of 0.95 m/s. what distance will in x will the second rock cover?

Apassenger walks toward the rear of a moving train. describe her motion as seen from a reference point on the train. then describe it from a reference point on the ground

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds