Advertisements
Advertisements
प्रश्न
Define work.
Define the term work
Advertisements
उत्तर
The work done by a force on a body is equal to the product of the force applied and the distance moved by the body in the direction of force i.e.,
Work done = Force × distance moved in the direction of force
APPEARS IN
संबंधित प्रश्न
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
An electron emitter must have _____________ work function and ___________ melting point.
The S.I. unit of work is
When does a force perform work?
State two conditions when no work is done by a force.
Write the expression for work done by a force.
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)
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
In case of negative work, the angle between the force and displacement is :
The work done on an object does not depend on the :
What is meant by a translational motion? Give one example.
A uniform circular motion is an accelerated motion. Justify it.
On what factors does the work done by a force depend?
Complete the following sentences:
The SI unit of work is ....... and of power is .......
Name the CGS unit of work.
State the energy changes which take place when A piece of magnesium wire is burnt in a jar of oxygen.
How much energy is gained by a box of mass 20 kg when a man, runs carrying the box with a speed of 3 m/s-1 to catch the bus?
State larger units of power.
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
What are the advantages and disadvantages of using solar cells for producing electricity?
Calculate the work done when:
A 5 kg weight is lifted 10 m vertically. (g = 9.8 m/s2)
A force is applied on a body of mass 20 kg moving with a velocity of 40 ms−1. The body attains a velocity of 50 ms−1 in 2 seconds. Calculate the work done by the body.
A force of F = (5y + 20) `hat"j"` N acts on a particle. The work done by this force when the particle is moved from y = 0 m to y = 10 m is ______ J.
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
