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F x Increase Decrease Remain the same f s Increase Decrease Remain the same F N

ID: 1589845 • Letter: F

Question

Fx

Increase

Decrease

Remain the same

fs

Increase

Decrease

Remain the same

FN

Increase

Decrease

Remain the same

fs, max

Increase

Decrease

Remain the same

If, instead, the box is sliding and is increased, does the magnitude of the frictional force on the box increase, decrease, or remain the same?

Increase

Decrease

Remain the same

In the figure, if the box is stationary and the angle between the horizontal and force is increased somewhat, do the following quantities increase, decrease, or remain the same?

Explanation / Answer

1) Fx:
writing the x component of the force Fx = F cos(theta).
Here the magnitude of the force F is constant but theta is increasing. We know that cos(theta) decreases with increase in theta. so Fx decreases.
2) fs:
The force of static friction increase with the requirement , here the requirement(i.e. Fx) is decreasing hence fs will decrease too.
3)FN
FN will depend on sin(theta) which increases with increase in angle theta, hence FN will increase.
4) fs max:
fs max depends on FN and mu_s and since mu_s is constant and FN is increasing, fs max will increase.
5) Yes because the normal force will be increasing hence mu_k times the normal force will increase and so as the friction force.