As the space shuttle reenters our planet’s atmosphere, its speed decreases becau

Question

As the space shuttle reenters our planet’s atmosphere, its speed decreases because of air friction from a reentry value V1=28600 Km/h to a landing speed V2=363 Km/h. Calculate the total heat produced by the loss of the kinetic energy. Assume only 2% of the total heat is absorbed by the shuttle and will increase its temperature. Calculate the increase in the shuttle temperature if it was made completely of steel. The shuttle mass is M=90,000 Kg and the specific heat capacity of steel is: C= 450 J/ (Kg K). Neglect the change in the potential energy

Explanation / Answer

Given, V1 = 28600 Km/h = 7944.4 m/s

  V2 = 363 Km/h = 100.83 m/s

  M = 90,000 Kg

  C= 450 J/ (Kg K)

Change in Kinetic Energy = 1/2*(M*V1^2) - 1/2*(M*V2^2)

        = 1/2*(90,000*7944.4^2) - 1/2*(90,000*100.83^2)

= 2.84*10^12 J

Now, The total heat produced = Change in Kinetic Energy = 2.84*10^12 J

Since, only 2 % of this energy is absorbed by the shuttle and will increase its temperature.

2 % of this energy = 2.84*10^12 J * 2/100 = 5.68*10^10 J

Now for the change in temperature,

Heat Energy = M*C*T

=> 5.68*10^10   = 90000*450*T

=> T = 1402 K

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.