Author Question: A 30-year-old astronaut goes off on a long term mission in a spacecraft that travels at speeds close ... (Read 52 times)

V@ndy87 · **on:** Jul 29, 2018

A 30-year-old astronaut goes off on a long term mission in a spacecraft that travels at speeds close to that of light. The mission lasts exactly 20 years as measured on Earth. Biologically speaking, the astronaut's age would be

A) more than 50 years.
B) exactly 50 years.
C) less than 50 years.
D) exactly 30 years.
E) exactly 25 years.

Question 2

One of the most efficient engines built so far has the following characteristics: combustion chamber temperature = 1900C; exhaust temperature = 430C. 7.0 109 cal of fuel produces 1.4 1010 J of work in one hour.

What is the power output, in hp, of this engine?