A 15kg object takes 26.3 meters to stop because of friction. Assume no skidding. If the frictional force is 60 N, what is the initial velocity of the object?

Answer 1

the work done in stopping is... f * d
... 60 * 26.3 = ? J

the work equals the initial kinetic energy of the object... ½ m v²

60 * 26.3 = ½ * 15 * v²

v = √(8 * 26.3) m/s

be aware of significant figures...