A 58.72 kg person holding a steel ball stands motionless on a frozen lake. The person then throws the ball, which propels the person at 1.05 m/s to the
right and the ball 3.75 m/s to the left. If the initial momentum of the system is
zero, what is the mass of the steel ball?

Ahollow metal sphere has 6 cm and 11 cm inner and outer radii, respectively. the surface charge density on the inside surface is −100nc/m2. the surface charge density on the exterior surface is:

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

The crank oa rotates in the vertical plane with a constant clockwise angular velocity ω0 of 5.6 rad/s. for the position where oa is horizontal, calculate the force under the light roller b of the 10.6-kg slender bar ab.