Pankaj Bhatt Solutions for Chapter: Force, Exercise 1: QUESTIONS

A nut can be opened by applying a moment at force $90\mathrm{Nm}$. If a mechanic can apply maximum force of $150\mathrm{N}$, what should be the length of lever to open the nut?

The figure shows wheel of radius $5\mathrm{cm}$ that can rotate freely about the point $O$. It is in equilibrium due to forces $F_1$ and  $F_2$ acting on it. Which one of $F_1$ and $F_2$ is greater force? What is the ratio of the two forces? Given $OO’=3\mathrm{cm}.$

A uniform metre scale rests on a knife edge at $60 \mathrm{cm}$ mark. The scale becomes horizontal when a mass of $12 \mathrm{g}$ is suspended from one end at scale. Which end of scale is this? What is the mass of scale?

The figure shows a heavy wheel of mass $w$ that can rotate freely about the axis passing through point $O$. The wheel is to be raised on the pavement $AB$ by applying a minimum force. Show the direction of application of force and calculate its magnitude.

The figure shows a bar $AB$ pointed in the middle at point $O$. Two forces $15 \mathrm{N}$ each act on this bar at ends$A$ and $B$ in opposite direction. What is magnitude of resultant moment of forces about $O$?

Three equal forces P. Q and R act in a plane but in different directions. The point O also lies in the same plane. Which force has the least moment about O? Which force has the largest moment about O? Give reasons to your answer.

A uniform metre scale balances horizontally at $44 \mathrm{cm}$ mark when a weight of $20 \mathrm{g}$ is placed at $15 \mathrm{cm}$ mark. What is weight of metre scale? Draw a diagram of arrangement.

Draw a neat labelled diagram to show the direction of two force $F_1$ and $F_2$, acting on a body produce rotation on it about point $O$. What happens when (i)$F_1=F_2$, and (ii) $F_1>F_2$