1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A mass of 2 kg is whirled in a horizontal circle by means of a string at an initial speed of 5 r.p.m. Keeping the radius constant the tension in the string is doubled. The new speed is nearly?

A
7 r.p.m.
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
14 r.p.m.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
10 r.p.m.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
20 r.p.m.
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A 7 r.p.m.mass=2kg Initialspeed=ω=5rpm=5×2π60radsec=π6radsecTension=Centripetalforce=mrω²T=2×r×(π6)²T=mrω²=2×r×π²36 If tension is doubled, centripetal force also will be doubled. 2T=mrω₁²=2×[2×r×π²36 where ω₁² is the new angular speed Dividing by we get ω₁²=2ω²ω₁=√2ω=√2×5≈7rpmNew angular speed will be √2times initial angular speed.

Suggest Corrections
0
Join BYJU'S Learning Program
Related Videos
PHYSICS
Watch in App
Explore more
Join BYJU'S Learning Program