Zero Work

Q.

A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is 25 joule, the angle which the force makes with the direction of motion of the body is

1. 30°

2. 60°

3. 0°

4. 90°

Q.

A man pushes a wall and fails to displace it. He does

1. Negative work

2. Positive but not maximum work

3. No work at all

4. Maximum work

Q.

A Man moves on a straight horizontal road with a block of 2kg in his hand. If he covers a distance of 20m with constant velocity of 1m/s. Find work done by man on block during motion.

1. 400J

2. 40J

3. zero

4. -10J

Q. A ball is connected to a rope and swung around in uniform circular motion. The tension in the rope is measured at 10 N and the radius of the circle is 1 m. How much work is done in one revolution around the circle?

1. 1
2. 0 (No Work)
3. 2
4. 3

Q. Kinetic friction can also do zero work.

1. True
2. False

Q. A block of mass $m$ is sliding down on a fixed inclined plane with velocity of $2\text{m/s}$ for a distance of $2\text{m}$. Angle of inclined plane is ${35}^{\circ }$. Calculate the work done by normal reaction on the block.

1. $0.5mg\sin {35}^{\circ }$
2. $0.5mg\cos {35}^{\circ }$
3. $2mg$
4. $0$

Q. A man weighing $50\text{kg}$ is walking on a horizontal surface (assumed smooth) for a distance of $1\text{km}$. What is the work done by his weight?

1. Zero
2. Nothing can be said
3. Positive
4. Negative

Q. At the point of contact, work done by the normal reaction when a person climbs up the stairs is

1. Zero
2. Positive
3. None of these
4. Negative

Q. An imaginery force $\overrightarrow{F}=\overrightarrow{B}\times \overrightarrow{V}$ given as the cross product of vector $\overrightarrow{B}$ (Force field) and $\overrightarrow{V}$ (velocity). Then the work done by the force is

1. Always equal to zero
2. Always less than zero
3. Always greater than zero
4. Can have any finite value

Q. What is work done by the force of tension$\left(T\right)$ in the string of a simple pendulum?

1. $TL$
2. Zero
3. $\frac{TL}{4}$
4. $\frac{TL}{2}$