A 50 kg student stands on a 4 kg skateboard at rest. The student catches a 9 kg backpack moving with a horizontal speed of 2 m/s in the direction the skateboard is free to roll. How fast will the student and the skateboard move after catching the backpack, assuming friction is negligible? Round your final answer to the hundredths place.

Balloon a has charge q, and identical mass balloon b has charge 10q. you hang them from threads near each other. choose all of the statements with which you agree. check all that apply. a. a and b exert the same magnitude forces on each other. b. the force that a exerts on b is 10 times the force that b exerts on a. c. the angle between the thread supporting a and the vertical is < the angle between the thread supporting b and the vertical. d. the force that a exerts on b is 1/10 the force that b exerts on a.

A( developed during the process of technology design

During a car accident, a 125kg driver is moving at 31m/s and in 1.5s is brought to rest by an inflating air bag. what is the magnitude of the change in momentum to the driver