English Medium Class 9 - CBSE Question Bank Solutions for Science

The distance between Delhi and Agra is 200 km. A train travels the first 100 km at a speed of 50 km/h. How fast must the train travel the next 100 km, so as to average 70 km/h for the whole journey ?

A train travels the first 15 km at a uniform speed of 30 km/h; the next 75 km at a uniform speed of 50 km/h; and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey.

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds: 

What is its average speed ?

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

How far does it travel in 1 second ?

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:
How far does it travel in 6 seconds ?

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

How long does it take to travel 240 m ?

A car travels 100 km at a speed of 60 km/h and returns with a speed of 40 km/h. Calculate the average speed for the whole journey.

A ball hits a wall horizontally at 6.0 m s^-1. It rebounds horizontally at 4.4 m s^-1. The ball is in contact with the wall for 0.040 s. What is the acceleration of the ball ?

Give one example of a motion where an object does not change its speed but its direction of motion changes continuously.

Write the formula to calculate the speed of a body moving along a circular path. Give the meaning of each symbol which occurs in it.

A train starting from rest moves with a uniform acceleration of 0.2 m/s² for 5 minutes. Calculate the speed acquired and the distance travelled in this time.

The tip of seconds’ hand of a dock takes 60 seconds to move once on the circular dial of the clock. If the radius of the dial of the clock be 10.5 cm, calculate the speed of the tip of the seconds’ hand of the clock. `("Given"  π= 22/7)`.

A car is moving on a straight road with uniform acceleration. The speed of the car varies with time as follows :
Time (s)              :     0          2         4          6       8         10
Speed (m/s)       :     4          8       12        16     20         24
Draw the speed-time graph by choosing a convenient scale. From this graph :

(1) Calculate the acceleration of the car.
(2) Calculate the distance travelled by the car in 10 seconds.

The graph given alongside shows how the speed of a car changes with time:

(i) What is the initial speed of the car ?
(ii) What is the maximum speed attained by the car ?
(iii) Which part of the graph shows zero acceleration ?
(iv) Which part of the graph shows varying retardation ?
(v) Find the distance travelled in first 8 hours.

A body is thrown vertically upwards. Its velocity keeps on decreasing. What happens to its kinetic energy as its velocity becomes zero?

Explain the following giving an example.

Saturated solution

Explain the following giving an example.

Suspension

Name the physical state of matter which can be easily compressed.

Name two gases which are supplied in compressed form in homes and hospitals.

Write the full forms of the following

1. LPG
2. CNG