The ratio of angular speed of the minute hand of clock to that of its hour hand is:
Correct answer: D. 12:1
- A. 3600:1
- B. 60:1
- C. 24:1
- D. 12:1
Explanation
The clock displays 12 divisions, which are 1 hour each for the hour hand and 5 minutes each for the minute hand. The minute hand completes 1 whole rotation of the 12 divisions for the hour hand to move 1 whole division; hence, the minute hand has to be 12 times faster than the hour hand.The minute hand of a clock completes one revolution (360 degrees) in one hour or 60 minutes. Therefore, its angular speed isωminute = (360 degrees) / (60 minutes) = 6 degrees per minuteThe hour hand of a clock completes one revolution in 12 hours or 720 minutes. Therefore, its angular speed is:ωhour = (360 degrees) / (720 minutes) = 0.5 degrees per minuteThe ratio of the angular speed of the minute hand to that of the hour hand is:ωminute / ωhour = (6 degrees per minute) / (0.5 degrees per minute) = 12Therefore, the ratio of the angular speed of the minute hand to that of the hour hand is 12:1.
Last updated
About Angular Velocity
Angular velocity describes how quickly angular displacement changes with time, with ω = Δθ/Δt and units of radians per second. Questions relate angular and linear motion through v = rω, use the direction given by the right hand rule, and distinguish angular velocity from angular acceleration and ordinary frequency.
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 body moves with constant angular velocity on a circle. Magnitude of angular acceleration is:
A body moving in a circle at constant speed
A body performing circular motion with a constant speed has a constant:
A fly wheel rotates at a constant speed of 3000rpm. The angle described by the shaft in radian in one second is:
A flywheel gains a speed of 540 rpm in 6 seconds. Its angular acceleration is: