Translational and Rotational Equilibrium

Q.

On what factors does centre of gravity depends ?

Q.

In the figure, a uniform bar of length $l$ m is supported at its ends and loaded by a weight $W$ kgf at its middle. In equilibrium, find the reactions $R_{1}and{R}_2$ at the ends.

Q.

A body of mass 1.50 kg is dropped from the 2nd floor of a building which is at a height of 12 m. The force acting on it during its fall? (g = 9.8 m s^-2)

1. 14.7 N

2. 176.4 N

3. 18N

4. 15 N

Q.

The mass is constant whereas the weight varies from place to place.

1. True
2. False

Q.

What type of machine is a nail.

Q.

If velocity (V), force(F) and time(t) are taken to be fundamental quantities and K is the dimensionless constant of proportionality, find the dimensional formula for mass.

1. [KVFT]

2. $\left[K{V}^{-1}F{T}^2\right]$

3. $\left[K{V}^{-2}FT\right]$

4. $\left[K{V}^{-1}FT\right]$

Q.

A book kept on the table is an example of :

1. neutral equilibrium

2. dynamic equilibrium

3. none of the above

4. static equilibrium

Q. For rotational equilibrium of a rigid body, it is essential that?

1. All of these
2. Net torque about points lying on axis of rotation must be zero.
3. Net torque about points lying on the body must be zero
4. Net torque about points lying outside the body must be zero

Q.

A, B and C are three forces each of magnitude 4 N acting in the plane of paper as shown in fig. Which force has the least moment about O and which force has the greatest moment about O?

1. C has the lest moment and B has the greatest moment

2. B has the least moment and C has the greatest moment

3. A has the least moment and B has the greatest moment

4. C has the least moment and A has the greatest moment

Q. Which of the following forces will generate the highest torque about the point O?

1. Force acting at A
2. Force acting at B
3. Force acting at C
4. All forces will generate torque of the same magnitude.

Q.

What is the principle behind beam balance?

Q.

On what factors does the position of the centre of gravity of a body depend ?

Q.

Which diagram shows the resultant force correctly ?

1. 
2. 
3. 
4. 

Q.

A rod of length 100 m is pivoted at a distance of 60 m from one end. A block of mass 10 kg is suspended at the other end of the rod. If the rod is in equilibrium, find the mass of the rod. Take acceleration due to gravity $g$ = $10m{s}^{-}2$

1. 20 kg

2. 30 kg

3. 40 kg

4. 60 kg

Q. Apparent motion is related with the:

1. Motion of the earth
2. Motion of the moon
3. Motion of the sun
4. Motion of stars

Q.

The unit of mass is kilogram, while that of weight is Newton. Explain.

Q.

A force of 10 N is applied to spin a potters wheel. If the diameter of the wheel is 60 cm, calculate the moment of force.

Q.

When slightly different weights are placed on the two pans of a beam balance, the beam balance comes to rest at an angle with the horizontal. The beam is supported at a single point P by a pivot. Then which of the following statement (s) is (or are) true?

1. The net torque about P due to the two weights is non-zero at the equilibrium position.

2. The whole system does not continue to rotate about P because it has a large moment of inertia.

3. The center of mass of the system lies below P.

4. The center of mass of the system lies above P.

Q.

A force to be expressed correctly requires

1. only the magnitude

2. only the direction

3. both the magnitude and direction

4. none of the above

Q. Write the relation between angular momentum and torque$.$ What is the torque acting on a body rotating with constant angular momentum$?$

Q.

Determine the moment of force about the bolt if you are pulling a wrench of length 0.25 m with a force of 300 N, perpendicular to the wrench

1. 25 Nm

2. 50 Nm

3. 75 Nm

4. 100 Nm

Q.

Which of the following beams is in equilibrium?

1. 
2. 
3. 
4. 

Q.

State the principle of moments?

Q.

Weight is the force with which _______ pulls bodies towards itself.

Q.

A door is pushed open by applying a force of 50 N at a point 50 cm from the hinges. What is the moment of the force?

1. 0.25 Nm

2. 2.5 Nm

3. 25 Nm

4. 2500 Nm

Q.

An object either will not be moving or moving at a constant angular velocity, then that object___

1. is in translational equilibrium

2. is in rotational equilibrium

3. is in both rotational and translational equilibrium

4. is not in equilibrium

Q.

What is principle of moments?

Q.

A boy weighing 600N was in a lift. The lift experienced a breakdown and started falling freely under the action of gravity, what would be the weight of the boy in the lift?

1. 100N

2. 0

3. Can't be Said

4. 600N

Q.

When a boy weighing $20kg$ sits at one end of a $4m$ long see-saw, it gets depressed at this end. How can it be brought to the horizontal position by another boy weighing$40kg$?

1. By sitting at a distance of $1m$ from the centre on the side opposite to the first boy.

2. By sitting at a distance of $1m$ from the centre on the same side as the first boy.

3. By sitting at a distance of $2m$ from the centre on the side opposite to the first boy.

4. By sitting at a distance of $2m$from the centre on the same side as the first boy.

Q.

When a cracker explodes into two equal parts, in which of the following ways will these parts move?

1. Opposite directions with equal velocities.

2. Opposite directions with unequal velocities.

3. Opposite directions with equal or unequal velocities.

4. Same direction with equal velocities.