Chapter 4, Problem 13RQ

Referring to Figure 4.13, how many forces are exerted on the cart? What is the horizontal net force on the cart?

To determine

The number of forces are exerted on the cart in figure 4.13, and the horizontal net force act on the cart.

Answer to Problem 13RQ

The force $P$ applied by the horse to pull the cart, the push $F$ of the horse and the cart on each other and the force of friction $f$ that is act between the cart wheels and the ground. And the net horizontal force is $F_{cart}=P-f$.

Explanation of Solution

The free body diagram of the cart is shown below,

The cart is subjected to three forces, the force $P$ applied by the horse to pull the cart, the push $F$ of the horse and the cart on each other and the force of friction that is $f$ act between the cart wheels and the ground.

The net horizontal force acting on the cart will be equal to difference of force applied by the horse to pull the cart and the friction force.

Write the expression for net horizontal force act on the cart.

$F_{cart}=P-f$

Conclusion:

Therefore, the force applied by the horse to pull the cart, the push of the horse and the cart on each other and the force of friction that is act between the cart wheels and the ground. And the net horizontal force is $F_{cart}=P-f$.