Q3 of 26 Page 28

Rewrite the following sentences using proper alternative.

If we increase the velocity of a car moving on a flat surface to four times its original speed, its potential energy….


i. will be twice its original energy


ii. will not change


iii. will be 4 times its original energy


iv. will be 16 times its original energy.

Option(ii) will not change

Explanation:


Potential energy of an object does not depend upon its speed but rather its depends on height of object of earth’s surface,its mass and , acceleration due to gravity g , which are constant i.e. does not change during motion of a car on a smooth road as We know the Relation for Potential energy of an object of mass m due to earth’s gravity(g is acceleration due to gravity) held at an height h above ground is


P.E. = mgh


i.e. more is the height of body from ground more is the potential energy and less is the height of body from ground less is the potential energy


now here height of car from ground is constant so potential energy is also same or will not change.


More from this chapter

All 26 →
3

Rewrite the following sentences using proper alternative.

The potential energy of your body is least when you are …..


i. sitting on a chair


ii. sitting on the ground


iii. sleeping on the ground


iv. standing on the ground

 3

Rewrite the following sentences using proper alternative.

The total energy of an object falling freely towards the ground …


i. decreases


ii. remains unchanged


iii. increases


iv. increases in the beginning and then decreases

 3

Rewrite the following sentences using proper alternative.

The work done on an object does not depend on ….


i. displacement


ii. applied force


iii. initial velocity of the object


iv. the angle between force and displacement.

 4

Study the following activity and answer the questions.

1. Take two aluminium channels of different lengths.


2. Place the lower ends of the channels on the floor and hold their upper ends at the same height.


3. Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.




Questions


At the moment of releasing the balls, which energy do the balls have?