Question

1. A 4 kg mass moves on a circular track of radius 2 m
with 120 rev/min its KE will be
(a) 25 (0) 32J (6) 80J (d) 1262 J
​

Answer 1

Answer:

ans is D

Explanation:

KE=0.5×mv^2

v=2×3.14÷t

120rev per min converted to rev per sec

so 120÷60=

t=2×3.14×r÷v