Advertisements
Advertisements
Question
The sign of work done by a force on a body is important to understand. State carefully if the following quantity is positive or negative:
Work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket.
Solution
The work done by a man in lifting a bucket out of a well by means of a rope tied to the bucket is positive. This is due to the fact that in order to lift a bucket out of a well, the person must exert a force that is equal to the bucket's weight vertically upward. Since the movement is also upward, the angle θ is 0°.
RELATED QUESTIONS
The geostationary orbit of the earth is at a distance of about 36000 km from the earth's surface. Find the weight of a 120-kg equipment placed in a geostationary satellite. The radius of the earth is 6400 km.
When you lift a box from the floor and put it on an almirah the potential energy of the box increases, but there is no change in its kinetic energy. Is it a violation of conservation of energy?
A particle is released from the top of an incline of height h. Does the kinetic energy of the particle at the bottom of the incline depend on the angle of incline? Do you need any more information to answer this question in Yes or No?
Can the work by kinetic friction on an object be positive? Zero?
Can static friction do nonzero work on an object? If yes, give an example. If no, give reason.
A particle of mass 500 gm is moving in a straight line with velocity v = bx5/2. The work done by the net force during its displacement from x = 0 to x = 4 m is : (Take b = 0.25 m-3/2 s-1).
In the given figure, the block of mass m is dropped from point 'A'. The expression for the kinetic energy of the block when it reaches point 'B' is ______.
The sign of work done by a force on a body is important to understand. State carefully if the following quantity is positive or negative:
Work done by gravitational force on a man in lifting a bucket out of a well by means of a rope tied to the bucket.
The sign of work done by a force on a body is important to understand. State carefully if the following quantity is positive or negative:
Work done by friction on a body sliding down an inclined plane.
The sign of work done by a force on a body is important to understand. State carefully if the following quantity is positive or negative:
Work done by the resistive force of air on a vibrating pendulum in bringing it to rest.
