A baseball is hit by a bat really hard and the ball is hit out of the park. What is experiencing a change in velocity? A) the ball that was thrown fast in the direction of the batter and then hit out of the park
B) the batter who was waiting to hit the ball
C) the person who threw the ball

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.