Work

Q.

Work done is _____ when there is no displacement

Q.

Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 2 meters?

1. Lifting 35 kg sack

2. Lifting 70 kg sack

3. Both require the same amount of work

4. In both cases work done is zero

Q.

Can an internal force change the velocity of a body?

Q.

Give one word for this-

Useful work done by the machine

Q. Which of the following is not correct about management?

1. Organising
2. Planning
3. Time wasting
4. Coordination

Q.

Lift your science book in your hand. Do you do any work?

Q.

The surface of tyres are made rough. Why?

Q.

Look at the activity listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.

Food grains are getting dried in the sun.

Q.

For the amount of work done to be 0, the net ___ in the direction of force should be 0.

1. displacement

2. speed

3. time

4. motion

Q.

How are normal and applied force different from each other?

Q. Spring force is an example of a variable force which is conservative .Justify the above statement.

Q.

Friction is a noncontact force

1. True
2. False

Q.

Which of the following is considered as work in terms of science?

1. Rohan lifitng his school bag

2. Roshan waiting at the bus stop

3. Pritish is thinking a lot to solve a question
4. Puja tries to push a wall which doesn't move

Q.

In which of the following situations is more work done?

1. Carrying a bag for 10 km

2. Carrying a bag for 9 km

3. Carrying a bag for 6 km

4. Carrying a bag for 3 km

Q.

When a body moves in a circular path, work done on it is _______.

Q.

Lifting a block of _______, the work done is maximum.

1. 10 kg

2. 8 kg
3. 6 kg

4. 2 kg

Q. The amount of money needed for a specific work should be estimated in advance.

1. True
2. False

Q.

Work = ___ $\times$ ___

Q. Identify the condition positive, negative and zero work done from the following.

1. Positive (III), negative (II), zero (I)
2. Positive (III), negative (I), zero (II)
3. Positive (I), negative (II), zero (III)
4. Positive (II), negative (I), zero (III)