A car travels at a constant speed on a flat, circular track. Which factor, when doubled, will decrease the centripetal force on the car?

Ben(55 kg) is standing on very slippery ice when junior(25kg) bumps into him. junior was moving at a speed of 8m/s before the collision and ben and junior embrace after the collision. find the speed of ben and junior as they move across the ice after the collision .

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Aplane travels 1000 miles in 5 hours .what is the planes average speed?