Translational Equilibrium Revisited

Q. $\text{O}$ is the centre of an equilateral triangle $\text{ABC}.F_1,F_2$ and $F_3$ are three forces acting along the sides $\text{AB, BC and AC}$ as shown in the figure. What should be the magnitude of $F_3$, so that the total torque about $\text{O}$ is zero ?

1. $F_1+F_2$
2. $F_1-F_2$
3. $\frac{(F_1+F_2)}{2}$
4. $\frac{(F_1-F_2)}{2}$

Q. A string wound round the rim of a mounted flywheel of mass 20kgand radius 20cm.A steady pull of 25 N is applied on the cord.Neglecting friction and mass of the string, the angular acceleration of the wheel is

Q.

Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?

Q.

State the relationship between force and other units

Q. Explain the turning effect of force and state the factors affecting it ??

Q. If the net force acting on a rigid body is zero, it implies that the centre of mass is either at rest or moving at with a constant velocity.

1. False
2. True

Q. For a rigid body at rest in ground frame, if sum of the torques is zero about some points, then

1. Net torque is zero about some points & nonzero about some points
2. Net torque would be zero or nonzero depending upon situation
3. Net torque is zero about all other points
4. Net torque is zero about no other points

Q. What is the torque produced by a force about the origin when it is directed towards the origin?

1. Positive
2. Negative
3. Zero
4. Depends, cannot say

Q. A regular hexagonal uniform block of mass $m=4\sqrt{3}\text{kg}$ rests on a rough horizontal surface with coefficient of friction $\mu$ as shown in figure. A constant horizontal force is applied on the block as shown. If the friction is sufficient to prevent slipping before toppling, then the minimum force is $F$ (in $\text{N}$) that is required to topple the block about its corner $\text{A}$. Find the value of $\frac{F}{10}$
(Take $g=10{\text{m/s}}^2$)

Q. If the net force acting on a rigid body is zero, it implies that the centre of mass is either at rest or moving at with a constant velocity.

1. False
2. True

Q.

If I consider thethe Newton's third law of motion, then is it enough for me to train just my legs and make them very strong, stronger than the other Sumo wrestler to defeat him in a fight? I mean being able to push him out of the ring?

Q. For a rigid body at rest in ground frame, if sum of the torques is zero about some points, then

1. Net torque is zero about all other points
2. Net torque is zero about no other points
3. Net torque is zero about some points & nonzero about some points
4. Net torque would be zero or nonzero depending upon situation

Q. Which one of the following statements is correct?

1. If the net external force on body is zero, then velocity of center of mass is zero.
2. Acceleration of a projectile is maximum at the highest point.
3. A body can be at rest or in motion at the same time depending upon frame.
4. A particle having constant speed can have acceleration.

Q. The body under zero net force can be considered in translation equilibrium.

1. False
2. True