English Medium Class 9 - CBSE Question Bank Solutions for Science

Fill in the following blank with suitable word :

If a body moves with uniform velocity, its acceleration is  ..............

Explain why, the motion of a body which is moving with constant speed in a circular path is said to be accelerated.

Find the initial velocity of a car which is stopped in 10 seconds by applying brakes. The retardation due to brakes is 2.5 m/s².

Describe the motion of a body which is accelerating at a constant rate of 10 m s^–2. If the body starts from rest, how much distance will it cover in 2 s ?

A motorcycle moving with a speed of 5 m/s is subjected to an acceleration of 0.2 m/s². Calculate the speed of the motorcycle after 10 seconds, and the distance travelled in this time.

A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.

A cheetah starts from, rest, and accelerates at 2 m/s² for 10 seconds. Calculate :
(a) the final velocity
(b) the distance travelled.

A train travelling at 20 m s^-1 accelerates at 0.5 m s^-2 for 30 s. How far will it travel in this time ?

Explain the meaning of the following equation of motion :v = u + at, where symbols have their usual meanings.

A body starting from rest travels with uniform acceleration. If it travels 100 m in 5 s, what is the value of acceleration ?

A bus was moving with a speed of 54 km/h. On applying brakes it stopped in 8 seconds. Calculate the acceleration.

Derive the formula : v = u + at, where the symbols have usual meanings.

Derive the formula s= `ut+1/2at^2` , where the symbols have usual meanings.

A train starting from stationary position and moving with uniform acceleration attains a speed of 36 km per hour in 10 minutes. Find its acceleration.

A car acquire a velocity of 72 km per hour in 10 second starting from rest. Find

(1) the acceleration,
(2) the average velocity, and
(3) the distance travelled in this time.

A car is travelling along the road at 8 ms^-1. It accelerates at 1 ms^-2 for a distance of 18 m. How fast is it then travelling ?

To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.

A boy is sitting on a merry-go-round which is moving with a constant speed of 10 m s⁻¹. This means that the boy is :

A freely falling object travels 4.9 m in 1st second, 14.7 m in 2 nd second, 24.5 m in 3rd second, and so on. This data shows that the motion of a freely falling object is a case of :

When a car driver travelling at a speed of 10 m/s applies brakes and brings the car to rest in 20 s, then retardation will be :