Advertisements
Advertisements
Question
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
Advertisements
Solution
Force applied by the car, (F) = 2.5 × 1010 N
Speed of the car, (v) = 5 m/s
Time taken, (t) = 120 s
So distance travelled,
Distance = Speed × Time
= 5 × 120 m
= 600 m
So, Work done = (Force) × (Distance)
= `2.5 xx 10^10 xx 600` J
= `1.5 xx 10^13` J
APPEARS IN
RELATED QUESTIONS
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
The moon is revolving around the earth in a circular path. How much work is done by the moon?
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The loss in potential energy of the body,
What happens to the work done when the dispacement of body is at right angles to the direction of force acting on it? Explain your answer.
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
Complete the following sentences:
Joule is the unit of .......
A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.
A cricket ball is thrown up from the earth's surface. What happens to its P.E.
(a) during the motion
(b) at the highest point?
Give an example
Chemical energy changes to heat energy.
