An object of mass 1 kg is whirled round in a horizontal circle of radius 0.5 m on the end of a rope. When it rotates at 4 rev/s, the tension in the rope is:
A) 8 N
B) 158 N
C) 316 N
D) 632 N

Question

Quizplus · Accepted Answer

The tension in the rope can be found using the centripetal force equation:

F = mv^2/r

where F is the centripetal force, m is the mass, v is the velocity, and r is the radius.

First, we need to find the velocity of the object at 4 rev/s:

v = 2πr/T

where T is the period of one revolution.

T = 1/f
T = 1/4 s
T = 0.25 s

v = 2π(0.5)/0.25
v = 12.57 m/s

Now we can calculate the tension:

F = mv^2/r
F = 1(12.57)^2/0.5
F = 316 N

Therefore, the answer is C, 316 N.

An Object of Mass 1 Kg Is Whirled Round in a Horizontal