Question
Define work and discuss when the work done is maximum and when it is zero.
✓
Answer
Work is said to be done only when the force applied on a body causes a displacement of the body in the direction of force or any resolved component of the force.
The work is maximum, when displacement is in the direction of applied force.
The work done is minimum when displacement is zero or displacement is normal to the direction of the applied force.
The work is maximum, when displacement is in the direction of applied force.
The work done is minimum when displacement is zero or displacement is normal to the direction of the applied force.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
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. Calculated:
(i) the work done, and
(ii) the power developed by each man. Take $g = 10N kg^{-1}.$
→(i) the work done, and
(ii) the power developed by each man. Take $g = 10N kg^{-1}.$
Define the term focal length of a lens.
Two musical notes of the same pitch and same loudness are played on two different instruments. Their wave patterns are as shown in following Figure.
Explain why the wave patterns are different.
Explain why the wave patterns are different.
How is the mechanical advantage related with the velocity ratio for an actual machine? State whether the efficiency of such a machine is equal to 1, less than 1 or more than 1.
(a) State the SI unit of electric work and define it.
(b) An electrical heater is rated $1000 W-200 V$. Calculate :
(i) the resistance of the heating element.
(ii) the current flowing through it
→(b) An electrical heater is rated $1000 W-200 V$. Calculate :
(i) the resistance of the heating element.
(ii) the current flowing through it
Explain the cause of dispersion of white light through a prism.
How is a cathode ray tube used to convert an electrical signal into a visual signal?
$(a)$ State the nature of the lens and the focal length if its power is $+4 D .$
$(b)$ The focal length of a concave lens is $10 \ cm$ . Calculate its power.
→$(b)$ The focal length of a concave lens is $10 \ cm$ . Calculate its power.
State four ways in which machines are useful to us?
A force $F$ acts on a body and displaces it by a distance $S$ in a direction at an angle $\theta$ with the direction of force. What should be the angle between force and displacement so that the work done is (i) zero, (ii) maximum?
→