Question
Physics Question on Uniform Circular Motion
A small block of mass 100 g is tied to a spring of spring constant 7.5 N/m and length 20 cm. The other end of spring is fixed at a particular point A. If the block moves in a circular path on a smooth horizontal surface with constant angular velocity 5 rad/s about point A, then tension in the spring is-
A
0.75N
B
1.5N
C
0.25N
D
0.50N
Answer
0.75N
Explanation
Solution
šš„ = šš^2 š
ā¹ šš„ = 0.1 Ć 25 Ć (0.2 + š„)
ā¹ 7.5š„ = 2.5(0.2 + š„) ā¹ 3š„ = 0.2 + š„
ā¹ 2š„ = 0.2 ā¹ š„ = 0.1š
Now, tension in the spring = šš„ = 7.5 Ć 0.1 š = 0.75 N