An astronaut is in equilibrium when he is positioned from the center of asteroid X and from the center of asteroid Y, along the straight line joining the centers of the asteroids. What is the ratio of the masses X/Y of the asteroids?

A) 0.0581
B) 17.2
C) 0.241
D) 4.15


Answer: A

Physics & Space Science

You might also like to view...

The statement "No detectable change in the total mass occurs during a chemical reaction" is known as the law of ______________

Fill in the blank(s) with correct word

Physics & Space Science

A(n) _________is a device that allows the angle of a sample relative to a reference to be changed and measured.

Fill in the blank(s) with the appropriate word(s).

Physics & Space Science

Potassium-40 decays to argon-40 has a half-life of 1.25 billion years. Suppose you find a rock that has only 1/8 of its original potassium-40 still remaining. How old is the rock?

A) 3.75 billion years B) 5.25 billion years C) 2.5 billion years D) 1.25 billion years E) 4.5 billion years

Physics & Space Science

Carbon dioxide gas at 1 atmosphere pressure it to be heated from 25°C to 75°C by pumping it through a tube bank at a velocity of 4 m/s. The tubes are heated by steam condensing within them at 200°C. The tubes have 10 mm OD, are in an in–line arrangement, have a longitudinal spacing of 15 mm and a transverse spacing of 17 mm. If 13 tube rows are required, what is the average heat transfer coefficient and what is the pressure drop of the carbon dioxide?

GIVEN
• In-line tube bank: condensing steam inside, CO2 outside
• CO2 temperatures
? In: (Tg,in) = 25°C
? Out: (Tg,out) = 75°C
• CO2 velocity (Us) = 4 m/s
• Steam temperature (Ts) = 200°C
• Tube outside diameter (D) = 10 mm = 0.01 m
• Longitudinal spacing (SL) = 15 mm = 0.015 m
• Transverse spacing (ST) = 17 mm = 0.017 m
• Number of tubes (N) = 13
FIND (a) The average heat transfer coefficient (hc) (b) The CO2 pressure drop (?p)
ASSUMPTIONS
• Steady state
• The thermal resistances of the condensing steam and the tube walls are negligible (tube wall temperature = Ts)
SKETCH

Physics & Space Science