A soccer ball weighing 0.15 kilogram is rolling with a speed of 10 m/sec and is stopped by the frictional force between it and the grass. If the average friction
force is 0.5 N, how long would this take?

Aproton is projected toward a fixed nucleus of charge +ze with velocity vo. initially the two particles are very far apart. when the proton is a distance r from the nucleus its velocity has decreased to 1/2vo. how far from the nucleus will the proton be when its velocity has dropped to 1/4vo?

What is the earliest point in the universe that we can observe? why can’t we see back further than this?

Suppose a soccer ball is kicked from the ground at an angle 20.0º above the horizontal at 8.00 m/s. the y-velocity is determined to be 2.74 m/s. how long will the ball be in the air? assume the ball lands at the same height at which it was kicked.