# Physics: Work and energy, linear momentum, and rotational motion

Problem1: A neutron in a nuclear reactor makes an elastic head-on collision with a carbon atom initially at rest. (the mass of the carbon atom is 12 times that of the neutron.) what fraction of the neutron's kinetic energy is transferred to tha carbon atom? (express your answer in percent)

Problem2: A 1400kg rocket sled at rest on level frictionless rails is loaded with 25kg of propellent. It exhaust the propellent in a 15 seconds "burn".The rocket moves at 160m/s after the burn. What average force is experienced by the rocket during the burn?

Problem3: A rotating flywheel can be used as a method to store energy. If the flywheel has 1.0*10^6joules of kinetic energy when rotating at 400 rad/s, and if a frictional torque of 4.o N-m acts on the system, in what interval of time would the flywheel come to rest?

Problem4: A baseball outfielder throws a baseball of mass 0.15kg at a speed of 40m/s and initial angle of 30 degrees. What is the kinetic energy of the baseball at the highest point of the trajectory? Ignore air friction.

Problem5: The bottom of a flat- bottom aluminium boat has an area = 5m^2 and the mass of the boat is 55kg. If two fisherman and their fishing gear with total mass of 475kg are placed in the boat, how much lower will the boat ride in water? (water density = 1000kg/m^3.

#### Solution Summary

With detailed calculations and good explanations, the problems are solved.