Drag Force

Q.

What Is Streamlining? How Is It Useful?

Q.

Give reason

The shape of boats and ships is streamlined.

Q. Suppose you want to level a field using a lawn roller. Would you prefer to push or pull it? Why?

1. only if the objects are solid
2. only if one of the two objects is liquid
3. only if one of the two objects is gaseous
4. irrespective of whether the objects are solid, liquid or gaseous

Q. The force which resists motion in a liquid is called___.

Q.

The statement given below is incorrect. Write the correct statement.

The boats are streamlined to give them better look.

Q. Drag is the force which resists or opposes motion in ___ (solids/fluids).

Q. The following is a conversation between three friends:

Ram – I am experiencing a force of friction
Pamela – I am experiencing an air drag
Nikita – I am experiencing viscosity

Choose the possible correct inferences from the options.

1. Ram might be under motion on the ground
2. Pamela might be falling freely from a height
3. Nikita might be swimming under water
4. Nikita might be at rest

Q.

Bodies of aircrafts are streamlined so as to

1. increase the air friction

2. reduce the air friction

3. make them attractive

4. make them slimmer

Q. What is meant by viscosity and coefficient of viscosity? Explain its cause and give its dimension and units.