In: Physics
A solid sphere of radius R, a solid cylinder of radius R, and a hollow cylinder of radius R all have the same mass, and all three are rotating with the same angular velocity. The sphere is rotating around an axis through its center, and each cylinder is rotating around its symmetry axis. Which one has the greatest rotational kinetic energy?
both cylinders have the same rotational kinetic energy
the solid cylinder
the solid sphere
they all have the same rotational kinetic energy
the hollow cylinder
for hollow cylinder I =MR2
for solid cylinder I. =1/2(MR)
for sphere I=2/5(MR2)
rotational k.e. directly proportional to I
hence hollow cylinder has highest k.e.