Advertisements
Advertisements
प्रश्न
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
Advertisements
उत्तर
- The work done is zero because the force acts perpendicular to the displacement.
Work done at angle θ = F × s × cosθ
W = F × s × cos90∘ - The work done is positive because the object's displacement occurs in the direction of the applied force.
- The work done is negative because the object's displacement occurs in the opposite direction of the applied force.
APPEARS IN
संबंधित प्रश्न
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
Fill in the blank with suitable word :
1 joule is the work done when a force of 1 __________ moves an object through a distance of one __________ in the direction of __________.
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
Fill in the boxe to show the corresponding energy transformation.
