
A sphere of mass m is tied to one end of a string of length l and rotated through the other end along a horizontal circular path with speed v. The work done in full horizontal circle is
A. 0
B. $({\dfrac{mv^2}{l}})^2$
C. 3
D. 2
Answer
162.9k+ views
Hint: To solve this problem, we should know about circular motion. Basic concepts regarding the circular motion and work done by a system moving in a circular motion. Here a sphere of mass is tied on a string and it is rotated in a circular path. We have to calculate the work done in a full horizontal circle.
Complete step by step solution:
Here a sphere of mass m is tied on a string of length l and it is rotated through the other end along a horizontal circular path and we have to calculate work done by the system in full horizontal circle.The particle moving in circular motion means centripetal force acting on the system.
Centripetal force is the force acting on a particle executing uniform circular motion and it is acting inwards. It restricts the movement of particles in a circle but it is not at all responsible for the displacement of particles. If no displacement takes place, then from definition of work centripetal force can’t do work. Therefore, work done by a centripetal force in uniform circular motion is equal to zero and the answer is: the work done in full horizontal circle is zero.
Therefore, the correct answer is option A.
Note: Usually, we go for the general equation for work done in these kinds of problems. We have that work done is equal to the product of force and distance travelled. But here answer is zero since work done by centripetal force in uniform circular motion is always equal to zero
Complete step by step solution:
Here a sphere of mass m is tied on a string of length l and it is rotated through the other end along a horizontal circular path and we have to calculate work done by the system in full horizontal circle.The particle moving in circular motion means centripetal force acting on the system.
Centripetal force is the force acting on a particle executing uniform circular motion and it is acting inwards. It restricts the movement of particles in a circle but it is not at all responsible for the displacement of particles. If no displacement takes place, then from definition of work centripetal force can’t do work. Therefore, work done by a centripetal force in uniform circular motion is equal to zero and the answer is: the work done in full horizontal circle is zero.
Therefore, the correct answer is option A.
Note: Usually, we go for the general equation for work done in these kinds of problems. We have that work done is equal to the product of force and distance travelled. But here answer is zero since work done by centripetal force in uniform circular motion is always equal to zero
Recently Updated Pages
JEE Main 2021 July 25 Shift 1 Question Paper with Answer Key

JEE Main 2021 July 22 Shift 2 Question Paper with Answer Key

JEE Atomic Structure and Chemical Bonding important Concepts and Tips

JEE Amino Acids and Peptides Important Concepts and Tips for Exam Preparation

JEE Electricity and Magnetism Important Concepts and Tips for Exam Preparation

Chemical Properties of Hydrogen - Important Concepts for JEE Exam Preparation

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility, & More

JEE Main 2025: Derivation of Equation of Trajectory in Physics

Displacement-Time Graph and Velocity-Time Graph for JEE

Degree of Dissociation and Its Formula With Solved Example for JEE

Electric Field Due to Uniformly Charged Ring for JEE Main 2025 - Formula and Derivation

Charging and Discharging of Capacitor

Other Pages
JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

NCERT Solutions for Class 11 Physics Chapter 1 Units and Measurements

Units and Measurements Class 11 Notes: CBSE Physics Chapter 1

Motion in a Straight Line Class 11 Notes: CBSE Physics Chapter 2

Important Questions for CBSE Class 11 Physics Chapter 1 - Units and Measurement

NCERT Solutions for Class 11 Physics Chapter 2 Motion In A Straight Line
