# Types of Force and its Effects

1.Which Force Can Be Used to Gather Iron Pins From a Mixture of Plastic and Iron Pins? Give a Reason for Your Answer.

Magnetic force can be used to gather iron pins from a mixture of plastic and iron pins. The reason is that iron pins are magnetic and are attracted by a magnet.

2.What Is Pressure?

The force acting on the unit area of an object is called pressure.

3.The force acting on the unit area of an object is called pressure.

The sofa springs get compressed due to the force applied while we sit on it.

4.What Is Atmospheric Pressure?

The force exerted due to the weight of air around us is called atmospheric pressure.

5.The force exerted due to the weight of air around us is called atmospheric pressure.

Atmospheric pressure comes into play in the following situations—

• Sucking a liquid through a straw.
• Filling a dropper with a liquid.
• Sticking a rubber sucker on the wall.

6.Why Does Our Body Not Collapse Due to the Force Exerted by Atmospheric Pressure?

Our body does not collapse due to the force exerted by atmospheric pressure as blood in our body also exerts pressure, called blood pressure. As a result, our body shape is maintained.

7.What Is the Unit of Force?

The unit of force is Newton.

8.What Happens if the Frictional Force Between the Wheels of a Trolley and the Floor Decrease?

If the frictional force between the wheels of a trolley and the floor decreases, the trolley cannot move smoothly on the floor.

9.Why Do Football Players Wear Spike Shoes While Playing Football?

Football players wear spike shoes as they increase the magnitude of frictional force between the feet and the ground and help them get a better grip on the ground while running.

10.Force Can Change the Shape of an Object. Give Examples to Prove This Fact.

The following examples state that force can change the shape of an object—

• Change is the shape of dough when rolled with a rolling pin.
• Change in the length of spring when stretched.
• Change in the shape of a sponge when pressed.

11.Why Does a Sharp Knife Cut Objects More Effectively Than a Blunt Knife?

Sharp knives have less area than blunt knives. While pressing a sharp knife, the force of our hand is distributed over a smaller area. Hence, more pressure is applied, helping cut an object easily.

Less pressure is produced when the force is distributed over a large area. Hence, objects are not cut properly using a blunt knife.

12.In Which of the Following Situations Will the Force Cause a Deeper Depression? Give a Reason for Your Answer.

i) A Man Standing on the Sofa. ii) a Man Lying on the Sofa.

13.What Will Happen if an Equal Magnitude of Force Is Applied From Both Sides of an Object?

There would be no change in the position of an object as equal magnitudes of force will neutralise the resultant force.

14. What Role Does Atmospheric Pressure Play in Our Daily Life?

Atmospheric pressure comes into play in the following situations—

• Sucking a liquid through a straw.
• Filling a dropper with a liquid.
• Sticking a rubber sucker on the wall.

15. What Happens to the Sofa Springs When We Sit on a Sofa?

The sofa springs get compressed due to the force applied while we sit on it.