English Medium Class 9 - CBSE Question Bank Solutions for Science

State the various effects of force.

Give one example  where  a force moves a stationary body.

Give one example where a force stops a moving body.

Give one example where a force changes the speed of a moving body.

Give one example  where a force changes the direction of a moving body.

Give one example where a force changes the shape (and size) of a body.

What do you understand by the terms “balanced forces” and “unbalanced forces” ? Explain with examples.

What type of forces – balanced or unbalanced – act on a rubber ball when we press it between our hands ? What effect is produced in the ball ?

What happens to the passengers travelling in a bus when the bus takes a sharp turn ? Give reasons for your answer.

Why are road accidents at high speeds very much worse than road accidents at low speeds ?

A car is moving on a level road. If the driver turns off the engine of the car, the car’s speed decreases gradually and ultimately it comes to a stop. A student says that two forces act on the car which bring it to a stop. What could these forces be ? Which of these two forces contributes more to slow down and stop the car ?

There are two types of forces X and Y. The forces belonging to type X can produce motion in a stationary object but cannot change the shape of the object. On the other hand, forces belonging to type Y cannot produce motion in a stationary object but can change the object. What is the general name of the forces as (a) X, and (b) Y?

What is the unit of force ?

What is the relationship between force and acceleration ?

A 1000 kg vehicle moving with a speed of 20 m/s is brought to rest in a distance of 50 metres :
(i) Find the acceleration.
(ii) Calculate the unbalanced force acting on the vehicle.

Name the quantity whose one of the units is pascal (Pa).

State the units in which pressure is measured.

What name is given to thrust per unit area ?

What force acting on an area of 0.5 m² will produce a pressure of 500 Pa ?

Fill in the blank with suitable word :
Force acting on a unit area is called...................