MODULE 5: Advanced Mechanics

Question 1

Explain what happens to a rocket’s chemical, kinetic and gravitaional potential energy

Answer 1

At launch, ignition of the fuel begins the conversion of chemical potential energy (fuel) to kinetic energy (exhaust gases). Impulse from the exhaust delivers energy to the rocket and work is done. The rocket then begins to move upward gaining GPE and KE. Chemical potential energy continues to reduce due to fuel consumption overtime, this is converted to kinetic energy, increasing speed and as the rocket gains an increase in altitude GPE increases.

Question 2

Compare the orbital velocity and orbital period of low Earth orbits and geostationary orbits and relate these to their use

Answer 2

the lower the orbital radius= the faster the satellite travels= lower orbital period

increase in velocity=decrease in time

Geostationary: GPS-> stays in a fixed position

LEO: fast and cheap communication, minimal delays mapping and monitoring

Question 3

Explain the energy transformations involved in placing a satellite into orbit and then maintaining this orbit

Answer 3

1. Potential chemical energy from fuel-> kinetic energy (exhaust gases)-> impulse from the exhaust gases delivers energy -> work is done fuel consumpiton increases KE and speed and increase in altitude increases GPE. When in orbit no work is required as the centripetal force is perpendicular to its force of motion W=Fcos(90)=0