English Medium इयत्ता ९ - CBSE Question Bank Solutions

Fill in the following blank with suitable word :

In a speed-time graph, the area enclosed by the speed-time curve and the time axis gives the…………….. by the body.

Name the property of bodies (or objects) to resist a change in their state of rest or of motion.

The mass of object A is 6 kg whereas that of another object B is 34 kg. Which of the two objects, A or B, has more inertia ?

With which physical quantity should the speed of a running bull be multiplied so as to obtain its momentum ?

Fill in the following blank with suitable word :
(a) ………………is a measure of the inertia of a body.

Name the two quantities, the slope of whose graph give acceleration.

A body of mass 25 kg has a momentum of 125 kg.m/s. Calculate the velocity of the body.

Calculate the momentum of the following :
(a) an elephant of mass 2000 kg moving at 5 m/s
(b) a bullet of mass 0.02 kg moving at 400 m/s

Describe the term ‘inertia’ with respect to motion.

On what factor does the inertia of a body depend ? Which has more inertia, a cricket ball or a rubber ball of the same size ?

Why do the passengers in a bus tend to fall backward when it starts suddenly ?

Explain why, a person travelling in a bus falls forward when the bus stops suddenly.

When a tree is shaken, its fruits and leaves fall down . Why ?

If the mass of a body and the force acting on it are both doubled, what happens to the acceleration ?

Draw a velocity-time graph to show the following motion :
A car accelerates uniformly from rest for 5 s ; then it travels at a steady’ velocity for 5 s.

The velocity-time graph for part of a train journey is a horizontal straight line. What does this tell you about the trains velocity.

The velocity-time graph for part of a train journey is a horizontal straight line. What does this tell you about its acceleration ?

Show by means of graphical method that: v = u + at, where the symbols have their usual meanings.

Show by using the graphical method that: `s=ut+1/2at^2` where the symbols have their usual meanings.

Derive the following equation of motion by the graphical method : v² = u² + 2as, where the symbols have their usual meanings.