5. A force probe is used to pull the block with a constant speed. The probe measures a force of 1.8 N. What is the size of the friction force you are pulling with? Explain how you came up

with this answer.

Frictional Force = 1.8 N

Explanation:

From Newton's Second Law, we know that the acceleration is produced in an object, whenever an unbalanced force is applied to it. So, for the production of acceleration application of an unbalanced force is necessary. Since, the block is moving with uniform speed in this case. Therefore, there is no acceleration involved in the motion of block. So, the all the forces acting on the block must cancel the effect of each other. So, that there is no unbalanced force to produce any acceleration. Therefore, the frictional force must be equal to the applied force in order to cancel its effect and balance it.

Frictional Force = Applied Force

Frictional Force = 1.8 N