Question

The Genesis spacecraft just crashed into the Utah desert. The craft has a speed of approximately 321 km/hr, and an approximate mass of 400 kg upon impact.

a.) If you assmue that it enters the atmosphere with a speed of 16 m/s, how far did it have to fall, in meters, to achieve that speed when colliding with the ground? (Ignore air resistance)

b.) After the impact the craft is stationary on the desert floor, what became of all the mechanical energy it had just before impact?

Please show step by step. Thank you!

Answer 1

a) mass of spacecraft, m = 400 kg, initial velocity, v_i = 16 m/s, final velocity, v_f= 321 km/hr = 89.167 m/s .

Let the spacecraft fall by a height "h" before reaching the final velocity.

By work energy theorem we have,

Work done by all forces = Change in kinetic energy

b) At the time of impact most the mechanical energy is transferred to the ground causing the spacecraft to dig into the ground. The ground then applies almost equivalent force thereby shattering the spacecraft into bits.  And the rest of the energy is dissipated into the surroundings in the form of heat and sound.