The moment of inertia of a body about a given axis 1.2 kg m 2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1500 J and angular acceleration of 25 rad / s 2 must be applied about the axis for a duration of:

Question

The moment of inertia of a body about a given axis 1.2 kg m 2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1500 J and angular acceleration of 25 rad / s 2 must be applied about the axis for a duration of: (A) 10 s (B) 8 s (C) 2 s (D) 4 s

Tardigrade Admin · Accepted Answer

Kinetic energy is given by E =(1/2) I ω2, ω2=(2 E/I) ω2 =(2 × 1500/1.2)=2500 ω =√2500=50 rad / sec t =(ω/α)=(50/25)=2 sec

Q. The moment of inertia of a body about a given axis $1.2 k g m^{2}$ . Initially the body is at rest. In order to produce a rotational kinetic energy of $1500 J$ and angular acceleration of $25 r a d / s^{2}$ must be applied about the axis for a duration of:

10 s

8 s

2 s

4 s

Kinetic energy is given by
$E = \frac{1}{2} I ω^{2}, ω^{2} = \frac{2 E}{I}$
$ω^{2} = \frac{2 \times 1500}{1.2} = 2500$
$ω = 2500 = 50 r a d / sec$
$t = \frac{ω}{α} = \frac{50}{25} = 2 sec$

Q. The moment of inertia of a body about a given axis 1.2kgm2. Initially the body is at rest. In order to produce a rotational kinetic energy of 1500J and angular acceleration of 25rad/s2 must be applied about the axis for a duration of:

10 s

8 s

2 s

4 s

Kinetic energy is given by E=21​Iω2,ω2=I2E​ ω2=1.22×1500​=2500 ω=2500​=50rad/sec t=αω​=2550​=2sec

Q. The moment of inertia of a body about a given axis $1.2 k g m^{2}$ . Initially the body is at rest. In order to produce a rotational kinetic energy of $1500 J$ and angular acceleration of $25 r a d / s^{2}$ must be applied about the axis for a duration of:

Kinetic energy is given by
$E = \frac{1}{2} I ω^{2}, ω^{2} = \frac{2 E}{I}$
$ω^{2} = \frac{2 \times 1500}{1.2} = 2500$
$ω = 2500 = 50 r a d / sec$
$t = \frac{ω}{α} = \frac{50}{25} = 2 sec$