Physics Answers

Oxygen, O2, at 200 bar is to be stored in a steel vessel at 20oC the capacity of the vessel

is 0.04m3

. Assuming that O2 is a perfect gas, calculate the mass of oxygen that can be

stored in the vessel. The vessel is protected against excessive pressure by a fusible plug

which will melt if the temperature rises too high. At what temperature must the plug

melt to limit the pressure in the vessel to 240bar? The molecular weight of oxygen is 32

(10.5 kg; 78.6oC)

A heat exchanger wall consists of a copper plate 20 mm thick. The heat transfer

coefficients on the two sides of the plate are 2700 and 7000 W/m2K, corresponding to

fluid temperatures of 92 °C and 32 °C, respectively. Assuming that the thermal

conductivity of the wall is 375 W/mK,

a. Calculate the surface temperatures in °C, and

b. Calculate the overall heat transfer in W/m2K.

What is the speed of a car that went 32 miles in 0.50h?

Ariel dropped a golf ball from her second story window. The ball starts form rest and hits the sidewalk 1.5 seconds later with a velocity of 14m/s. Find the avarage acceleration of the golf ball

a diver of mass 80kg,steps off a diving board at point a 4,0 m above the level of the water of a swimming pool.the diver enters the water at point b and comes to rest at point c.while the diver falls through the air,an average frictional force of magnitude 172n acts on the diver. the total work done on the diver by no conservative forced while he moves from a to c is -6240j

A particle travels at 1.90×10⁸ m/s and lives 2.10×10⁻⁸ s when at rest relative to an observer. How long does the particle live as viewed in the laboratory?

c = 3.0×10⁸

If astronauts could travel at v=0.950 c, we on Earth would say it takes 4.42 years to reach Alpha Centauri. The astronauts disagree.

 How much time passes on the astronauts' clocks?

c = 3×10⁸

The control panel on a spaceship contains a light that blinks every 2.00 s as observed by an astronaut in the ship. If the spaceship is moving past Earth with a speed of 0.750 c, determine the time interval between blinks as observed by a person on Earth.

c = 3times10^8

Roger is travelling with a speed of 0.800c relative to Mia. Roger travels for 50.0 s as measured on his watch.

 Calculate the elapsed time on Mia’s watch during this motion.

c = 3.0 ×

10⁸

What distance separates two objects of equal mass (5 kg) that are experiencing a gravitational force of 100 N?