Starting from rest, a basketball rolls from the top to the bottom of a hill, reaching a translational speed of 7.6 m/s. Ignore frictional losses. (a) What is the height of the hill? (b) Released from rest at the same height, a can of frozen juice rolls to the bottom of the same hill. What is the translational speed of the frozen juice can when it reaches the bottom?

Respuesta :

Answer:

(A) h = 4.9 m v

(B) = 8 m/s

Explanation:

translational speed = 7.6 m/s

(A) from the conservation of energy equation

  mgh = (mv^{2} / r) + (Iw^{2} / r)  

  where the moment of inertial (I) = (2mr^{3}) / 3

  mgh = \frac{mv^{2}}{r} + \frac{\frac{2mr^{3}}{3} x w^{2} }{r}

  mgh = m (\frac{v^{2}}{r} + \frac{\frac{2r^{3}}{3} x w^{2} }{r} )

  gh = \frac{5V^{2}}{6}

  g =  \frac{5V^{2}}{6g}

  h =  \frac{(5) x (7.6)^{2}}{6 x 9.8}

  h = 4.9 m

(B) just as from in (A) above, using the conservation of energy equation with      (I) being close to mr^2 / 2

mgh =  (mv^{2} / r) + (1/2)(mr^{2}/2)(v/r)^{2}

v = [tex]\sqrt{\frac{4gh}{3} }[/tex]

v = [tex]\sqrt{\frac{4 x 9.8 x 4.9}{3} }[/tex]

v = 8 m/s