Another toboggan with a mass of 30 kg, is being accelerated at 40 cm/s^2 by two boys pulling ropes at an angle of 20(degrees) with the direction of travel. They are each pulling with a force of 25 N.

a) what is the force of friction?

b) if, after reaching of 3.0 m/s, the boys stop pulling, how far will the toboggan slide?

c) how much time will this slide take?

See:

http://www.jiskha.com/display.cgi?id=1287524844