A wheel of radius R and mass M is placed at the bottom of a fixed step of height R as shown in the figure. A constant force is continuously applied on the surface of the wheel so that it just climbs the step without slipping. Consider the torque $τ$ about an axis normal to the plane of the paper passing through the point Q. Which of the following options is/are correct?

Question

Aicharya · Accepted Answer

(i) is incorrect.

If force is applied normal to surface at point $X$

$τ = F_{y} R \sin θ$

Thus $τ$ depends on $θ$ and it is not constant

(ii) is incorrect

If force applied tangentially at S

$τ = F \times R \neq 0$

But it will climb as mentioned in question.

If force is applied normal to surface at P then line of action of force will pass from Q and thus $τ = 0$

(iv) is incorrect.

If force is applied at P tangentially the $τ = F \times 2 R = c o n s t a n t$

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A wheel of radius R and mass M is placed at the bottom of a fixed step of height R as shown in the figure. A…

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