(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Physics

Show that gravity decreases at higher altitudes.

Find the initial velocity of a car which is stopped in 10 seconds by applying brakes. Retardation due to brakes is 2.5 ms^-2.

Name the agent which decomposes animal dung into biogas.

Which component of biogas is used as a fuel?

What is biogas?

Write any two uses of biogas.

Define the terms : time period as related to a simple pendulum.

How is the time period of a simple pendulum affected, if at all, in the following situations:

1. The length is made four times.
2. The acceleration due to gravity is reduced to one-fourth.

How do you measure the time period of a given pendulum? Why do you note the time for more than one oscillation?

Two simple pendulums A and B have lengths 1.0 m and 4.0 m, respectively, at a certain place. Which pendulum will make more oscillations in 1 min? Explain your answer.

State how does the time period of a simple pendulum depend on (a) length of pendulum, (b) mass of bob, (c) amplitude of oscillation and (d) acceleration due to gravity.

A simple pendulum completes 40 oscillations in one minute. Find its (a) Frequency and (b) Time period.

A body moving with a constant acceleration travels distances 3 m and 8 m, respectively in 1 s and 2 s. Calculate:

1. The initial velocity.
2. The acceleration of body.

Describe a fixed dome type biogas plant with the help of a labelled diagram.

Give four reasons, why the use of cowdung in biogas preferred to burning of cowdung cakes.

Multiple choice Question. Select the correct option.

A driver applies brakes when he sees a child on the railway track, the speed of the train reduces from 54 km/h to 18 km/h in 5 s. What is the distance travelled by train during this interval of time?

A boy drops a stone from a cliff, reaches the ground in 8 seconds. Calculate

1. final velocity of stone
2. height of cliff. (Take g = 9.8 ms⁻²)

A stone thrown vertically upwards takes 4 s to return to the thrower. Calculate

1. initial velocity of the stone
2. maximum height attained by stone. (Take g = 10 ms⁻²)

A spaceship is moving in space with a velocity of 50 kms⁻¹. Its engine fires for 10 s, such that its velocity increases to 60 kms⁻¹. Calculate the total distance travelled by a spaceship in 1/2 minute, from the time of firing its engine

Derive the equations
(i) v= u+at and
(ii) v²-u²= 2as, where the symbols have their usual meanings.