A particle performs uniform circular motion with angular momentum 'L'. If the frequency of the particle's motion is halved and its KE is doubled then the angular momentum becomes:
Correct answer: B. 4L
- A. L/4
- B. 4L
- C. 2L
- D. L/2
Explanation
For a rotating particle KE = ½ I ω² and L = I ω, so L = 2K/ω. If K → 2K and ω → ω/2 then L(new) = 2(2K)/(ω/2) = 4·(2K/ω)/2 = 4 L. Thus the angular momentum becomes four times the original.
Last updated
About Angular and Linear Quantities
Rotational motion relates angular displacement, angular velocity and angular acceleration to linear displacement, tangential velocity and tangential acceleration through the radius. Questions use radians, v equals r omega and tangential acceleration, while distinguishing tangential velocity from centripetal acceleration and angular quantities from their linear counterparts.
Practise Rotational and Circular Motion
521 free Rotational and Circular Motion MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A 1000 kg vehicle is turning around a corner at 10 m/s as it travels along an arc of a circle. If the radius of the circular path is 10 m, how large a force must be exerted by the pavement on the tires to hold the vehicle in the circular path?
A 400 gram ball is tied to the end of a cord and whirled in à horizontal circle of radius 0.6 m. If the ball makes five complete revolutions in 2 s, what is the ball's linear speed?
A 500 kg car takes a round turn of radius 50 m with a velocity of 36 km/hr. :The centripetal force is
A 800 kg car is turning round a corner at 6 m/sec as it travels along an arc of circle of radius 12 m. The magnitude of force exerted by pavement on the tyres to hold the car in circular path is _.
A ball of mass 0.25kg attached to the end of a string of length 1.96m is moving in a horizontal circle. The string will break if the tension is more than 25N. What is the maximum speed at which the ball can be moved?