g A wheel of rotational inertia 16 kg·m2 is subjected to a net torque of 24 N·m. The wheel starts at rest. After the torque has acted for 5.0 s, at what rate is work being done by the torque?

Respuesta :

Answer:

P = 180 watts

Explanation:

It is given that,

Inertia of the wheel, [tex]I=16\ kgm^2[/tex]

Net torque acting on the wheel, [tex]\tau=24\ Nm[/tex]

Initial speed of the wheel, [tex]\omega_i=0[/tex]

Time, t = 5 s

We know that the relation between the torque and the angular acceleration is given by :

[tex]\tau=I\alpha[/tex]

[tex]\alpha[/tex] is the angular acceleration

[tex]\alpha =\dfrac{\tau}{I}[/tex]

[tex]\alpha =\dfrac{24\ Nm}{16\ kgm^2}[/tex]

[tex]\alpha =1.5\ rad/s^2[/tex]

Using first equation of rotational kinematics as :

[tex]\omega_f=\omega_i+\alpha t[/tex]

[tex]\omega_f=1.5\times 5[/tex]

[tex]\omega_f=7.5\ rad/s[/tex]

We know that the rate at which the work is done by the torque is called the power of any object. Its formula in rotational motion is given by :

[tex]P=\tau \times \omega_f[/tex]

[tex]P=24\ Nm\times 7.5\ rad/s[/tex]

P = 180 watts

So, the power of the wheel is 180 watts. Hence, this is the required solution.