Question

1. force diagram of a horse pulling a cart at a constant speed: a. what forces are acting on the object? 1 b. are these forces balanced? why? 2 c. what is the net force on the object? 1 d. is the objects motion changing or remaining unchanged? how do you know from the given information? 2 e. is the object accelerating? 1

Explanation:

Step1: Identify forces

The forces acting on the cart are the pulling - force of the horse ($F$), the frictional force ($F_F$), the normal force ($N$) exerted by the ground on the cart, and the weight ($W$) of the cart and its contents.

Step2: Check force balance

Since the cart is moving at a constant speed, according to Newton's first law, the forces are balanced. In the horizontal direction, $F = F_F$ (to counter - act friction), and in the vertical direction, $N=W$ (to counter - act the weight).

Step3: Calculate net force

The net force ($F_{net}$) on an object with balanced forces is zero. In the horizontal direction $F_{net,x}=F - F_F=0$, and in the vertical direction $F_{net,y}=N - W = 0$. So, $F_{net}=0$.

Step4: Analyze motion

The object's motion is remaining unchanged. Because a constant speed means no change in the magnitude of velocity, and since the forces are balanced, there is no change in the direction of motion either.

Step5: Determine acceleration

Acceleration ($a$) is related to net force by $F_{net}=ma$. Since $F_{net} = 0$, then $a = 0$.

Answer:

a. The forces are the pulling - force of the horse ($F$), frictional force ($F_F$), normal force ($N$), and weight ($W$).
b. Yes, because the cart is moving at a constant speed. In the horizontal direction, the pulling - force equals the frictional force, and in the vertical direction, the normal force equals the weight.
c. The net force is 0.
d. The object's motion is remaining unchanged. This is known because the object is moving at a constant speed and the forces are balanced.
e. No, since the net force on the object is 0 and $F_{net}=ma$, so $a = 0$.