Advertisements
Advertisements
Question
The world record for weight lifting was held by Sergei Didyk of the USSR. He lifted 261 kg to a height of 2.3 m in 4s; find:
(a) Weight lifted by him
(b) Work done by him
(c) Power developed by him. (g = 10m/s2)
Solution
(a) Weight lifted by him = m × g = 261 × 10 = 2610 N.
(b) Work done by him = F × d = 261 × 2.3 J = 6003 J.
(c) Power developed by him =`("Work in J")/("Time in s")=6003/4"Watt"` = 1500.75 W.
APPEARS IN
RELATED QUESTIONS
A body is moved in a direction opposite to the direction of force acting on it. State whether the work is done by the force or work is done against the force
The work done by a fielder when he takes a catch in a cricket match, is negative. Explain.
Name two places in india where electricity is generated from nuclear power plants.
State the factors on which moment of force about a point depends.
What do you mean by uniform circular motion?
A boy takes 3 minutes to lift a 20 litre water bucket from a 20 m deep well, while his father does it in 2 minutes. Compare:
- the work, and
- power developed by them.
Give the units of couple.
In the following case write yes, if the work is being done and no if no work is being done.
A man moving on the rough ground.
What is the S.I. unit of work? Define it.
A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.
