Since the cart is moving at a constant velocity, the forces are balanced. The forces acting on the cart are the force of friction (opposing the motion) and the sum of the forces applied by the two librarians pulling the cart.
Let's consider the forces in the horizontal direction:
- The force of friction opposes the motion and is equal in magnitude to the force applied by the librarians pulling the cart
- The force applied by the first librarian is 25 N [forward]
- The force applied by the second librarian is 32 N [forward]
The net force in the horizontal direction is the combined force applied by the librarians:
Net force = 25 N + 32 N = 57 N
Since the cart moves at a constant velocity, the forces are balanced:
Force of friction = 57 N
The force of friction is related to the coefficient of kinetic friction (μ) and the normal force (Fn) by the equation:
Force of friction = μ * Fn
The normal force (Fn) is equal to the weight of the cart and books:
Fn = mass * gravity acceleration
Fn = 35 kg * 9.8 m/s^2 = 343 N
Now we can solve for the coefficient of kinetic friction (μ):
57 N = μ * 343 N
μ = 57 N / 343 N
μ ≈ 0.17
Therefore, the coefficient of kinetic friction for the cart on the surface it is moving on is approximately 0.17.
Two librarians pull forward on a cart filled with books to bring them to a storage room. One librarian pulls with 25 N [forward] and the other pulls with 32 N [forward]. The total mass of the cart and books is 35 kg. The cart moves at a constant velocity.
Find the coefficient of kinetic friction.
1 answer