How did henry cavendish discover the value of g and earth's mass?

Aball is thrown straight up into the air with a speed of 21 m/s. if the ball has a mass of 0.1 kg, how high does the ball go? acceleration due to gravity is g = 9.8 m/s^2. a. 22.5 m b. 20.0 m c. 25.0 m d. 17.5 m

Relative to the ground below, how many joules of potential energy does a 1000-kg boulder have at the top of a 5-m ledge?

There are multiple tuning forks present in the room, and annie strikes one with a natural frequency of 400 hz. which of these other tuning forks will begin to vibrate through resonance and make the sound louder? a 200 hz tuning fork a 400 hz tuning fork a 800 hz tuning fork a 1600 hz tuning fork