Asked in PMC Practice Test 14 (2021) 2021Moderate

The tyres on a bicycle have a diameter of 24 inches. If the tyres are turning at a rate of 50 revolutions per minute, determine the bicycle's speed in miles per hour (mph).

Correct answer: D. 3.6

  • A. 3.1
  • B. 6.3
  • C. 3.9
  • D. 3.6

Explanation

Given that, diameter 24 inches. Hence the radius 24/2 = 12 inches. 1 revolution = 2πr = 2(π)(12) = 24π. If one revolution covers 24 inches then 50 revolutions cover 1250π inches. 1-24π. 50-x. x = 50x24π. x = 1250π. x = 3927. 50 revolution/minute = 3926.9 inches/minute. 1 Mile has 63,360 inches. 1 inch will have 1/63360miles. 1 hour has 60 minutes. 1 minute has 1/60 hour. Converting 3926.9 in/min into miles/hour will give 3.6 miles/hour. The bicycle is travelling at "3.6 mi/h".

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