When is the angular momentum of a system constant? a. when the total kinetic energy is constant. b. when no net external force acts on the system. c. when the linear momentum and the energy are constant. d. when no net torque acts on the system. e. when the moment of inertia is constant.

Agymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular velocity of 2rev/s. during the dismount she stretches out into the straight position, with a length of 1.5m, (assume she is a uniform rod through the center) for her landing. the gymnast has a mass of 50kg. what is her angular velocity in the straight position?

Arowboat passenger uses an oar to push the boat off the dock by exerting a force of 40n for 3.0s. what impulse acts on the boat.

Most of the volume of an atom is occupied by the