physics
posted by christina .
You push a 45 kg wooden box across a wooden floor at a constant speed of 1.0 m/s. The coefficient of kinetic friction is 0.15. Now you double the force on the box. How long would it take for the velocity of the crate to double to 2.0 m/s?

When the applied force doubles, the friction force will remain the same but the net force will go from zero to a new value equal to the friction force, M*g*Uk.
The acceleration rate will be
a = Fnet/m = m g *Uk /m = g Uk
Require that a*T = delta V = 1.0 m/s, and solve for T