1.

•An air hockey table works by pumping air through thousands of tiny holes in a table to support the light pucks. This allows the pucks to move around on cushions of air with very little resistance. One of these pucks has a mass of .25 kg and is pushed along by a 12.0 N force for 9.0 s.

•What is the puck’s final velocity?

With the equations friction=mu.normal force; fnet=ma=w+f; w=mg; friction=ma=fnet how do i find this?

would the acceleration be 48? (12 divided by .25; fnet=ma) but i am not sure. and i have no idea how to find the final velocity. i have the other equations to use but i am going to assume you know them. is there another variable that I am missing or something? what are all the given variables from the question? please reply; thanks.

### 1 Answer

1. We have m=.25 kg

F= 12 N , so acceleration (a)= F/m= 12/.25= 48m/s^2

as we know v=u+at (V,u, final & initial velocity respectively)

v= 0 + 48 * 9 (we assume that the particle starts from rest.)

=> Final velocity (v)= 432 m/s

Dear, we have assumed that there no friction force, the surface is smooth. But its an ideal situation. We have to find friction force if coefficient is given. And it will reduce the net force.

like F net= F applied- F friction

Thank You!