An astronaut holds a rock 100m above the surface of planet x. the rock is then thrown upward with a speed of 15 m/s, as shown in the figure. the rock reaches the ground 10s after is thrown. the atmosphere of planet x has a negligible effect on the rock when it is in free fall.

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.)