If a man pushes a heavy cart with a force of 200 newtons on the cart to keep it moving at a constant velocity, what is the frictional force between the cart and the ground? Is this kinetic or static friction? please explain because i really don't understand how to do this. and i was sick this week
2007-03-01 05:52:08 · 4 answers · asked by gayle325 1 in Science & Mathematics ➔ Physics
The cart can only move at constant velocity if the net force acting on it is zero. So the frictional force must be equal to the applied force but acting in the opposite direction. The answer is 200N.
Since the cart is moving the friction is kinetic friction. Kitetic friction is less then static friction, that is, it's easier to keep the cart going while it's moving then to make it start to move from rest!
2007-03-01 06:07:46 · answer #1 · answered by physicist 4 · 0⤊ 0⤋
P = kN = F; where P is the push = 200 Newtons and F is the force of friction found from k, the friction coefficient, and N the normal weight of the cart. Thus the friction force is 200 Newtons. Why?
The cart is not accelerating; so f = ma = 0 = P - F; where f is the net force acting on the cart, m is its mass, and a = 0 its acceleration. In other words, the push force P and the friction force F are equal and opposite forces giving a net force f = 0.
This is kinetic friction (sometimes called rolling friction) because v > 0, where v is the velocity of the cart. As KE = 1/2 mv^2, the kinetic energy, that cart of m mass has kinetic energy; thus the name kinetic friction.
2007-03-01 14:14:29 · answer #2 · answered by oldprof 7 · 0⤊ 0⤋
200N of friction force. kinetic friction.
If the cart is moving at constant velocity, then the forces acting on it must be balanced. Newton's laws of motion explain that unbalanced forces will always cause acceleration which is a change in velocity. So the friction pushing backward must be exactly equal to the force that the man is applying forward.
It would be kinetic friction. Kinetic friction is usually friction on moving objects. Static friction is usually friction on stationary objects. The cart is moving, so . . . kinetic friction and 200N of it.
2007-03-01 14:10:24 · answer #3 · answered by Christopher L 2 · 0⤊ 0⤋
As the cart moves with constant velocity, resultant force on the cart is zero.The friction is kinetic, because the cart is in motion hence kinetic friction equals force applied by the man i.e.200N
2007-03-01 14:02:10 · answer #4 · answered by ukmudgal 6 · 0⤊ 0⤋