Question

The moment of inertia of a body about a given axis is 1.2 kg m². Initially, the body is at rest . In order to produce a rotational kinetic energy of 1500 J, an angular acceleration of 25 rad s⁻² must be applied about that axis for a duration of(a) 4 s(b) 2 s(c) 8 s(d) 10 s

Answer 1

Sorry I don't know the answer refer to others

Answer 2

Answer:

B) 2 seconds

Explanation:

Inertia of the body = 1.2 kg m² (Given)

Angular acceleration = 25 rad s⁻² (Given)

E = 1/2ω²

= 1500 = 1/2×1.2ω²

= ω² = 3000/1.2

= ω² = 2500

= ω = 50 rads⁻1

t = ω/α ( because ω = 0+at)

t = 50/25

t = 2

Therefore, the duration for the axis should be 2 seconds