posted by Melissa .
A woman pushes a refrigerator across the floor at a steady speed of 20cm/s . If she has to push with a horizontal force of 400 N to keep it moving , is the force of friction less than 400 N , 400 N, more than 400 N, why
For zero acceleration, the net force must be zero. What does that tell you about the friction force?
The force of friction is zero?
constant velocity means NET force of zero.
That means the push exactly balances friction
so friction force is -400 if F is +400