A disk and a hoop roll without slipping down the incline plane, starting from rest at height h=0.55m above the level surface. Using the laws of energy conservation find the speeds of the objects at the bottom of the incline.

Respuesta :

Answer:

[tex]v = \sqrt{\frac{1.1g}{(1 + \frac{1}{r^2})}}[/tex]

Explanation:

By the law of energy conservation, the potential energy can be converted to kinetic energy and rotational energy as it rolling downhill

[tex]E_p = E_k + E_r[/tex]

[tex]mgh = 0.5mv^2 + 0.5m\omega^2[/tex]

Also velocity of the disk is its angular velocity times its radius:

[tex]gh = 0.5v^2 + \frac{v^2}{2r^2}[/tex]

[tex]gh = (\frac{v^2}{2})(1 + \frac{1}{r^2})[/tex]

[tex]v^2 = \frac{2gh}{(1 + \frac{1}{r^2}})[/tex]

[tex]v = \sqrt{\frac{2gh}{(1 + \frac{1}{r^2})}}[/tex]

[tex]v = \sqrt{\frac{1.1g}{(1 + \frac{1}{r^2})}}[/tex]