Question

a certain string 500 cm long breaks under a tension of 45 kg.wt .An object of mass 100g is attached to this string and whirled in a horizontal circle to find the maximum number of revolutions that the object can make per second without breaking the string​

Answer 1

Answer:

Answer

Correct option is

B

4.729

As given that breaking tension of string is 45kgwt=45×10N=450N so the tension in the string when we rotate the mass should be less than 450N

⇒T≥mω

2

R

⇒ω≤

mR

T

given that m=0.1kg, R=5m

⇒ω≤

0.1×5

450

⇒ω≤

900

⇒ω≤30rad/s

as we know r.p.s.(revolution per sec)×2π=ω

⇒r.p.s.=

2π

ω

=

2π

30

=4.729