A solid sphere of radius 35 cm is positioned

at the top of an incline that makes 20 ◦
angle
with the horizontal. This initial position of
the sphere is a vertical distance 3.4 m above
its position when at the bottom of the incline.
The sphere is released and moves down the
incline. 35 cm
M
µ
ℓ
20 ◦
3.4 m
Find the speed of the sphere when it reaches
the bottom of the incline if it rolls without
slipping. The acceleration of gravity is
9.8 m/s
2
and the moment of inertia of a sphere
with respect to an axis through its center is
2
5
M R2
.
Answer in units of m/s.