Question

Q.4) SAFEFind the angular
momentum of a body of mass 200
gm attach to string of length 4 m
revolve in horizontal Circle if the
string break under tension of 40 kg
of weight. WORKING LOAD (SWL)​

Answer 1

A certain string breaks under a tension of 45kgwt. A mass of 100g is attached to this string of length 500cm and whirled in a horizontal circle. Find the maximum number of revolutions per second without breaking the string.

Explanation:

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