Advertisements
Advertisements
प्रश्न
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
An engine is pulling a train.
Advertisements
उत्तर
- An engine applies force to pull the train. This allows the train to move in the direction of force.
- Therefore, there is a displacement in the train in the same direction.
- Hence, work is done by the engine on the train.
APPEARS IN
संबंधित प्रश्न
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B does the same in 15 s. Compare the work done.
A bullet of mass 0.5 kg slows down from a speed of 5 m s-1 to that of 3 m s-1. Calculate the change in kinetic energy of the ball.
Is work a scalar or a vector quantity?
A uniform circular motion is an accelerated motion. Justify it.
What is the SI unit of work?
Distinguish between work and power.
Fill in the boxe to show the corresponding energy transformation.

In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
