Answer:
a. The net force acting on the wagon is zero
b. The value of the force of friction is 25 N
c. The effect would be is the frictional force must be increase
Explanation:
Lets explain how to solve the problem
A horizontal force of 25 N is required to push a wagon across a sidewalk
at a constant speed
a.
→ Constant speed means acceleration is zero
→ Force = mass × acceleration
→ Force = mass × 0
→ Force = 0
<em>The net force acting on the wagon is zero</em>
b.
The wagon moves with constant speed, then
→ ∑ force = 0
There are two forces acting on the wagon external force of 25 N,
and the frictional force which is opposite to the direction of motion
→ 25 - Frictional force = 0
→ Frictional force = 25 N
<em>The value of the force of friction is 25 N</em>
c.
The force increased to 30 N
If the wagon still moves with constant speed
Due to Newton's law ∑ force in the direction of motion = mass ×
acceleration, but acceleration is 0 because the wagon moves with
constant speed, then ∑ F = 0
So the frictional force must increase to 30 N
<em>The effect would be is the frictional force must be increase</em>
<em></em>
<em>If the frictional force does not increase the wagon will accelerate</em>
