A student designs an investigation to study the effect of gravity on objects on Earth. He will use the criteria shown. How can the student improve the investigation? (1 point)

by dropping the balls from the same height

by finding balls made from different materials

by using balls that are the same mass

by measuring the circumference of the balls

Will give brainliest! jay rides his 2.0-kg skateboard. he is moving at speed 5.8 m/s when he pushes off the board and continues to move forward in the air at 5.4 m/s. the board now goes forward at 13 m/s. a. determine jay’s mass. b. determine the change in the internal energy of the system during this process.(express your answer to two significant figures and include the appropriate units.)

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

Question part points submissions used suppose that 2 j of work is needed to stretch a spring from its natural length of 26 cm to a length of 36 cm. (a) how much work is needed to stretch the spring from 28 cm to 32 cm? (round your answer to two decimal places.)