Question

question 9
1 pts
a sled is pulled by a tension force of 180 newtons. if the friction force is equal to 180 newtons, what can we say about the sleds motion?
the sled is not in equilibrium. the sled is accelerating because the net force on the sled is not equal to zero.
the sled is in equilibrium. it is either moving at a constant speed in a straight line, or it is at rest.

Explanation:

Step1: Calculate net force

The net force $F_{net}$ on an object is the vector - sum of all forces acting on it. Here, the tension force $F_T = 180$ N and the friction force $F_f=180$ N act in opposite directions. So, $F_{net}=F_T - F_f$.
$F_{net}=180 - 180=0$ N.

Step2: Apply Newton's first law

According to Newton's first law of motion, if the net force on an object is zero, the object is in equilibrium. An object in equilibrium is either at rest or moving with a constant velocity (constant speed in a straight - line motion).

Answer:

The sled is in equilibrium. It is either moving at a constant speed in a straight line, or it is at rest.