For the following situations given the system described, whichof the quantities listed should be zero? For those that are notzero, provide its sign. (External work, change in kinetic energy,change in gravitational potential energy, change in elasticpotential energy, change in thermal energy)
a. System: Ice skater. Situation: (Initial state = Ice skater atrest on ice, final state: ice skater at high speed on the ice)
b. System: Ice skater + ice rink. Situation: (Initial state =Ice skater at rest on ice, final state: ice skater at high speed onthe ice)
c. System: Earth + comet. Situation: (Initial state = comet isfar from earth, final state = comet has fallen to Earth, rightbefore it impacts the ground)
d. System: Earth + hanging spring with mass attached. Situation:(Initial state = mass at rest at equilibrium position, final state= mass at rest with spring fully compressed)
