Moment of inertia of a body about a given axis is 1.5 kg m2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1200 J, the angular acceleration of 20 rad/s2 must be applied about the axis for a duration of seconds.

Question

Moment of inertia of a body about a given axis is 1.5 kg m2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1200 J, the angular acceleration of 20 rad/s2 must be applied about the axis for a duration of seconds. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

ω = α t = 20t Given, (1/2) Iω2 = 1200 or (1/2) × 1.5 × (20t)2 = 1200 or t = 2 s

Q. Moment of inertia of a body about a given axis is $1.5 k g m^{2}$ . Initially the body is at rest. In order to produce a rotational kinetic energy of $1200 J$ , the angular acceleration of $20 r a d / s^{2}$ must be applied about the axis for a duration of _______ seconds.

$ω = α t = 20 t$
Given, $\frac{1}{2} I ω^{2} = 1200$
or $\frac{1}{2} \times 1.5 \times (20 t)^{2} = 1200$
or $t = 2 s$

Q. Moment of inertia of a body about a given axis is 1.5kgm2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1200J, the angular acceleration of 20rad/s2 must be applied about the axis for a duration of _______ seconds.

ω=αt=20t Given, 21​Iω2=1200 or 21​×1.5×(20t)2=1200 or t=2s

Q. Moment of inertia of a body about a given axis is $1.5 k g m^{2}$ . Initially the body is at rest. In order to produce a rotational kinetic energy of $1200 J$ , the angular acceleration of $20 r a d / s^{2}$ must be applied about the axis for a duration of _______ seconds.

$ω = α t = 20 t$
Given, $\frac{1}{2} I ω^{2} = 1200$
or $\frac{1}{2} \times 1.5 \times (20 t)^{2} = 1200$
or $t = 2 s$