Asphere consists of a solid wooden ball of uniform density 800kg/m3 and radius 0.30 m and is covered with a thin coating of lead foil with area density 20kg/m2. calculate the moment of inertia of this sphere about an axis passing through its center.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?