A 0.5kg football thrown by Tony Romo with a velocity of 15 m/s is caught by a stationary receiver and brought to rest in 0.02 seconds. a) what impulse is delivered to the ball? b) how much force must be exerted in order to stop the ball? The answers are -7.5kg m/s and F = -375N, but I don't know how they got them. Steps please! Thank you!!

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

In automobile steering wheel is shown what is the ideal mechanical advantage blank? if the ama is eight what is the efficiency of the steering wheel?

Lacie kicks a football from ground level at a velocity of 13.9 m/s and at an angle of 25.0° to the ground. how long will the ball be in the air before it lands? how far will the football travel before it lands?