Work Done against Gravity

Q.

A Porter lifts a luggage of 15 kg from the ground and puts it on his head 1.5 m above the ground. Calculate the work done on the luggage.

Q.

What is the work done by the force of gravity when a stone of mass is 250 g is thrown up through a height of 2.5 m?

Q.

An object of mass 15 Kg is at a certain height above the ground. If the gravitational P.E. is 480 J, find the height( in meter) at which the object is w.r.t the ground(g=10m/s²)

Q. A block of mass 5kg is lifted vertically upwards to a height of 1.5m at a constant speed.
What is the work done by the applied force

Q.

An object of mass 1. 5 kg is lifted to a height of 2 m by a man who imparts a constant force of 100n.find work done by gravity in process.(answer isn't 200j or 30j)

Q. please explain GRAVITATIONAL POTENTIAL ENERGY? AND PROVE THAT IT DOESN'T DEPENDS UPON PATH ?

Q. What will be the work done by the gravity when a body of mass m is raised to height h?

1. -mgh
2. 2mgh
3. zero
4. mgh

Q. A mass of 10kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force?

Q.

Pick the correct option(s) representing the unit of work.

1. Joule

2. Newton-metre

3. Watt

4. Metre per second

Q.

A boy of mass 40kg climbs up the stairs and reaches the roof at a height 8m in 5s.Calculate :

1-the force of gravity acting on the boy

2-the work done by him against the gravity

3-the power sent by the boy

(take g=10m 1/s²)

Q. Expression for the gravitational potential energy of an object at a height explain I can't understand

Q.

A book of masses 100g is raised to the top of a table of a height 1 m find the magnitude of the work done by the force applied against the gravitational force equal to g =10m/s²

Q. Ajit carries a load of 17 kg from the ground on his head and takes it to the heights of 2 m from the ground. Calculate the work done by him.

1. 34 J
2. 17 J
3. 333.2 J
4. 0 J

Q.

A boy lifts a 1 kg block by 1 m. The work done by the boy is:

1. 0 J
2. 1 J
3. 9.8 J
4. 0.1 J

Q.

A body of mass m falls down through a height h. Find the work done by gravity.

1. 4mgh

2. 2mgh

3. 

4. mgh

Q.

A load of 100 kg is pulled up by 5 m. Calculate the work done. Take $g=9.8m{s}^{-2}$

1. 4800 J

2. 4700 J

3. 4900 J

4. 5000 J

Q.

A man lifts a luggage of $10kg$ from the ground and puts it on his head $1.7m$ above the ground. Calculate work done by him on the luggage. Take acceleration due to gravity$=10m{s}^{-2}$.

1. $180J$

2. $200J$

3. $150J$

4. $170J$

Q.

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.$(takeg=10m{s}^{-2})$

1. 50 J

2. 100 J

3. 250 J

4. 500 J

Q. Unit(s) of work done is:

1. Watt
2. Ampere
3. Joule
4. Newton

Q. The work done by gravitational force is path independent.

1. True
2. False

Q.

When a stone tied to a string is whirled in a circle, the work done on it by the string is:

1. Positive

2. Negative

3. Zero

4. Undefined

Q.

A man weighing 70 kg carries a weight of 10 kg to the top of tower 100 m high. Calculate the work done.

Q. Work done by gravitational force is equal to the change in magnitude of potential energy of the body.

1. False
2. True

Q.

A body moves in a vertical semicircle of radius r from the lowest point to highest point. What is the amount of work done? (Assume mass of the body to be 'm' kg and acceleration due to gravity to be $gm{s}^{-2}$)

1. 2mgr

2. mgr

3. mgr

4. 2mgr

Q. Calculate the increase in mass when a body of rest mass 1 kg is lifted up through 1 m near the earth's surface.

1. $21\times {10}^{-16}kg$.
2. $1\times {10}^{-16}kg$.
3. $1.11\times {10}^{-16}kg$.
4. $51\times {10}^{-16}kg$.