Spacecraft Reentry. A spacecraft made of aluminum circles the earth at a speed of 7700 m/s. (a) Find the ratio of its kinetic energy to the energy required to raise its temperature from 0°C to 600°C. (The melting point of aluminum is 660°C. Assume a constant specific heat of 910 J/kg · K.) (b) Discuss the bearing of your answer on the problem of the re-entry of a manned space vehicle into the earth ’s atmosphere.

Solution 93P Problem (a) Step 1: Speed of the aircraft v = 7700 m/s Specific Heat capacity of Aluminium c = 910 J/Kg.K T = 0°C 1 T = 600°C 2 Step 2: To find the ratio of kinetic energy to the energy required to increase temperature from 0 °C to 600°C K.E 2mv2 Q = m.c.T 2 K.E = v Q 2.c(T2T1) Step 3: Substituting the values KQE = 2 910 (6000) * * K.E = 54.3 Q the ratio of kinetic energy to the energy required to increase temperature from 0°...