ICSE Class 6 Physics Important Questions Chapter 5 Pressure

Physics ICSE Class 6 Important Questions Chapter 5 Pressure

Practice Questions

Question 1.
Why do army tanks move on caterpillar tracks and not on ordinary wheels ?
Answer:
Army tanks are often required to move in marshy and uneven areas. They need to be prevented from sinking in the marshy areas. Therefore, they have broad steel tracks called catepillar tracks under their wheels. This increases the surface area of contact and thus reduces the pressure on the ground.

Question 2.
A brick is 20 cm long, 10 cm wide and 5 cm thick and weighs 15 N. It is kept on the ground with one of its 20 cm x 5 cm face in contact with the ground. What amount of pressure will the brick exert on the ground ?
Answer:
Force applied by the brick (F) = 15 N
Area of contact (A) = 20 cm x 5 cm
= \(\frac {20}{100}\) m x \(\frac {5}{100}\) m
= 0.2 m x 0.05 m = 0.01 m²
We know, P = \(\frac {F}{A}\) = \(\frac {15}{0.01}\)N/m² = 1500 Pa

Question 3.
Ajay popped a balloon by poking it with a pencil tip. If the area of the pencil tip is 0.01 m² and the pressure exerted by the pencil on the balloon is 10 Pa, find the force applied by Ajay on the pencil.
Answer:
Pressure exerted by the pencil = 10 Pa
Area of the tip of the pencil = 0.01 m²
We know, Pressure =
Or, Force = Pressure x Area
= 10 x 0.01 N = 0.1 N
Hence, force applied by Ajay is 0.1 N.

Question 4.
A bronze statue weighs 4800 N and it exerts a pressure of 24000 Pa on the ground on which it stands. Find the area of its base.
Answer:
Force applied by the statue on the ground = 4800 N
Pressure exerted by the statue on the ground = 24,000 Pa
As, Pressure =
So, Area = = \(\frac {4800}{24,000}\)m² = 0.2m²
Hence, area of the base of the statue is 0.2 m².

Question 5.
Fill in the blanks :
1. Smaller the area on which a force acts, ………… is the effect of the force.
Answer:
Smaller the area on which a force acts, greater is the effect of the force.

2. The total force acting on a given surface is known as ………….
Answer:
The total force acting on a given surface is known as thrust.

3. The effect of force depends upon the ………….. of the force applied.
Answer:
The effect of force depends upon the magnitude of the force applied.

4. …………… invented an early calculator and conducted , experiments on atmospheric pressure by constructing mercury barometers.
Answer:
Blaise Pascal invented an early calculator and conducted experiments on atmospheric pressure by constructing mercury barometers.

ICSE Class 6 Physics Important Questions