Question

the turntable in a microwave oven has a moment of inertia of 0.040 and rotates continuously, making a complete revolution every 4.0s. what is its kinetic energy

Answer 1

Kinetic energy is
`0.049\ kg \ m^2.`

Step-by-step explanation:

Given :

Moment of inertia of turntable in a microwave oven,
`I = 0.040\ kg \ m^2`.

Time period of rotation , T = 4 s.

Now , we know angular frequency ,
`\omega=(2 \pi)/(T)`.

Putting value of T in above equation.

`\omega=(2 * 3.14)/(4)=1.57\ rad/s.`

Now, Kinetic energy of rotating object,
`K.E=(1)/(2) I\omega^2`

Putting value of I and
`\omega` in above equation.

We get,

`K.E=(1)/(2)* 0.040* 1.57^2=0.049\ kg \ m^2.`

Hence, this is required solution.