An object of mass m is tied to a string of length l and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle θ with the vertical. Workdone by the force F is:

Question

An object of mass m is tied to a string of length l and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle θ with the vertical. Workdone by the force F is: <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/6f4743e207033897e4fb03488039e888-.png" /> (A) mgl (1- sin θ) (B) mgl (C) m g l(1- cos θ) (D) m g l(1+ cos θ)

Tardigrade Admin · Accepted Answer

Since there is no change in kinetic energy, work done by the force is equal to change in potential energy.

Q. An object of mass $m$ is tied to a string of length $l$ and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle $θ$ with the vertical. Workdone by the force $F$ is:

$m g l (1 - sin θ)$

$m g l$

$m g l (1 - cos θ)$

$m g l (1 + cos θ)$

Since there is no change in kinetic energy, work done by the force is equal to change in potential energy.

Q. An object of mass m is tied to a string of length l and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle θ with the vertical. Workdone by the force F is:

mgl(1−sinθ)

mgl

mgl(1−cosθ)

mgl(1+cosθ)

Since there is no change in kinetic energy, work done by the force is equal to change in potential energy.

Q. An object of mass $m$ is tied to a string of length $l$ and a variable horizontal force is applied on it which is initially zero and gradually increases until the string makes an angle $θ$ with the vertical. Workdone by the force $F$ is:

$m g l (1 - sin θ)$

$m g l$

$m g l (1 - cos θ)$

$m g l (1 + cos θ)$