A solid, uniform sphere of mass 2.0 kg and radius 1.8 m rolls from rest without slipping down an inclined plane of height 7.5 m. What is the angular velocity of the sphere at the bottom of the inclined plane

Respuesta :

Answer:

[tex]w^2=5.5rads/s[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=2.0kg[/tex]

Radius [tex]r=1.8m[/tex]

Height [tex]h=7.5m[/tex]

Generally the equation for Potential energy is mathematically given by

Potential energy=Kinetic energy+Rotational energy

 [tex]mgh=\frac{1}{2}mv^2+\frac{1}{2}Iw^2[/tex]

Since there is no slipping

 [tex]v=rw[/tex]

Therefore

 [tex]mgh=\frac{1}{2}mr^2w^2+\frac{1}{2}Iw^2[/tex]

Where

      [tex]I=\frac{1}{2}mr^2[/tex]

      [tex]l=3.24m[/tex]

 [tex]2*9.81*7.5=\frac{1}{2}(2)(1.8)^2w^2+\frac{1}{2}(3.24)w^2\\\\[/tex]

 [tex]147.15=3.24w^2+1.62w^2[/tex]

 [tex]w^2=\frac{147.15}{4.86}[/tex]

 [tex]w^2=\sqrt{\frac{147.15}{4.86}}[/tex]

 [tex]w^2=5.5rads/s[/tex]