Advertisements
Advertisements
प्रश्न
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
Advertisements
उत्तर
The relation between work, force, distance and angle between the two is:
W = (F) (S) cos θ
Where,
(W) - Work done
(F) - Force
(S) - Displacement
(θ) - Angle between force and displacement
Let us see the graph of to understand the dependence of work on the angle between force and distance.
From the graph, we can observe that on increasing the value of angle between force and distance, value of cos θ continuously decreases and becomes negative after `pi/2`.
Hence, if we increase the angle between force and distance gradually, the value of work done will continuously decrease.
APPEARS IN
संबंधित प्रश्न
Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.
Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.
A boy of mass 40 kg climbs up the stairs and reaches the roof at a height 8 m in 5 s. Calculate:
- the force of gravity acting on the boy,
- the work done by him against the force of gravity,
- the power spent by boy. (Take g = 10 m s-2)
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
Can work done be zero even if force acts on the body?
An object is dropped from a height H. when is its
(i) P.E. maximum,
(ii) K.E. maximum,
(iii) P.E. = K.E.?
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
Explain, why submarines are able to dive underwater as well as a sail on the surface of the water?
