Advertisements
Advertisements
प्रश्न
What is the condition for a force to do work on a body?
Advertisements
उत्तर
The necessary condition for force to do work is that the applied force should produce motion in the body in any direction except the direction perpendicular to the force applied.
APPEARS IN
संबंधित प्रश्न
A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
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,
Name the physical quantity whose MKS units are kgm2s-3.
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
Give an example
Electrical energy changes of sound energy.
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
