Advertisements
Advertisements
Question
Solution
Moment of force = applied force x perpendicular distance from the pivot
= 10 x 30 x 10 -2
= 3 Nm
APPEARS IN
RELATED QUESTIONS
Explain briefly why the work done by a fielder when he takes a catch in a cricket match is negative.
The energy of a body is its capacity to do .........
A man lifts a mass of 20 kg to a height of 2.5 m. Assuming that the force of gravity on 1 kg mass is 10 N, find the work done by the man.
What are the units of (a) work, and (b) energy?
A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. If the value of g be 10 m/s2, the work done by the girl against the gravitational force will be :
When you move upstairs, do you perform some work?
Give two examples of work done.
Name the physical quantity associated with the 'rate of doing work'.
List any six forms of energy and write a short note on each of them.
Fill in the boxe to show the corresponding energy transformation.
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
An engine is pulling a train.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Food grains are getting dried in the sun.