KE = 1/2(100 kg)(100 m/s)^2 = 500000 Joules ----------------------- KE = 1/2(100 kg)(50 m/s)^2 = 125000 Joules ---------------------- 5â¦00000 Joules/125000 Joules = 4 ------ The kinetic energy is reduced by a factor of 4 because the speed is squared.
Earth, the fifth-largest of the eight planets in the Solar System belongs to the Milky Way galaxy and is orbiting about 28,000 light years from the center of the galaxy. It is believed that currently it lies about 20 light years above the galaxy's equatorial plane in the Orion spiral arm.
Rare Earth suggests that much of the known universe, including large parts of our galaxy, cannot support complex life; Ward and Brownlee refer to such regions as dead zones.