A 250 g , 25-cm-diameter plastic disk is spun on an axle through its center by an electric motor. Part A What torque must the motor supply to take the disk from 0 to 1700 rpm in 4.5 s?

Respuesta :

Answer:

0.3086Nm

Explanation:

Given mass [tex]m=0.25kg[/tex], Radius [tex]r=0.25m[/tex]:

#Angular acceleration

[tex]\alpha=\frac{1700-0}{4.5}=377.78\ rpm/s=6.2963\ rot/s\\\\=6.2963\times 2\pi\\\\=39.5610rad/s\\[/tex]

Moment of inertia of the disk

[tex]I=0.5mr^2\\\\=0.5\times 0.25\times 0.25^2\\\\=0.0078 kg-m^2[/tex]

The torque required is therefore:

[tex]=I_\alpha=0.0078\times39.5610\\\\=0.3086\ Nm[/tex]

Hence, the torque required is 0.3086Nm