English Medium कक्षा ९ - CBSE Question Bank Solutions

What is the range of frequencies associated with infrasound?

What is the range of frequencies associated with ultrasound?

A person has a hearing range from 20 Hz to 20 kHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m s⁻¹.

Name the physical quantity which is considered to be a measure of the quantity of motion of a body.

What is the SI unit of momentum ?

state whether momentum is scalar or vector.

What is the total momentum of the bullet and the gun before firing ?

Name the physical quantity whose unit is kg.m/s.

Explain why, it is easier to stop a tennis ball than a cricket ball moving with the same speed.

Explain the meaning of the following equation : .
p = m x v
where symbols have their usual meanings.

Explain how, a karate player can break a pile of tiles with a single blow of his hand.

Calculate the momentum of a toy car of mass 200 g moving with a speed of 5 m/s.

What is the change in momentum of a car weighing 1500 kg when its speed increases from 36 km/h to 72 km/h uniformly ?

What is the momentum in kg.m/s of a 10 kg car travelling at (a) 5 m/s (b) 20 cm/s, and (c) 36 km/h ?

Define momentum of a body. On what factors does the momentum of a body depend ?

Calculate the change in momentum of a body weighing 5 kg when its velocity decreases from 20 m/s to 0.20 m/s.

A plastic ball and a clay ball of equal masses, travelling in the same direction with equal speeds, strike against a vertical wall. From which ball does the wall receive a greater amount of momentum ?

A man throws a ball weighing 500 g vertically upwards with a speed of 10 m/s.

1. What will be its initial momentum ?
2. What would be its momentum at the highest point of its flight ?

Which physical quantity corresponds to the rate of change of momentum ?

State the relation between the momentum of a body and the force acting on it.