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

First, we need to calculate the total force applied to the cart:

Total force = 25 N + 32 N
Total force = 57 N

Next, we need to calculate the force of friction acting on the cart. Since the cart is moving at a constant velocity, the force of friction is equal in magnitude and opposite in direction to the total force applied by the librarians.

Force of friction = Total force
Force of friction = 57 N

Next, we can calculate the gravitational force acting on the cart:

Gravitational force = mass * acceleration due to gravity
Gravitational force = 35 kg * 9.81 m/s^2
Gravitational force = 343.35 N

Now, we can calculate the normal force acting on the cart:

Normal force = gravitational force
Normal force = 343.35 N

Finally, we can calculate the coefficient of kinetic friction using the formula:

Coefficient of kinetic friction = Force of friction / Normal force
Coefficient of kinetic friction = 57 N / 343.35 N
Coefficient of kinetic friction ≈ 0.166

Therefore, the coefficient of kinetic friction for the cart and books is approximately 0.166.