Consider three galaxies, Alpha, Beta and Gamma. An astronomer in Beta sees each of the other two galaxies moving away from him in opposite directions at 0.70c. At what speed would an observer in Alpha see the galaxy Gamma moving?
A) 1.4c B) 0.94c C) 0.98c D) 0.82c E) 0.70c
B
You might also like to view...
Which of the following reaction energies is the most endothermic?
A) 540 kJ/mole B) -540 kJ/mole C) 125 kj/mole D) -125 kJ/mole E) not enough information given
Two cylindrical resistors are made of the same material and have the same resistance. The resistors, R1 and R2, have different radii, r1 and r2, and different lengths, L1 and L2 . Which of the following relative values for radii and lengths would result in equal resistances?
a. r1 = r2 and 4L1 = L2 c. 2r1 = r2 and 4L1 = L2 b. r1 = r2 and L1 = 2L2 d. 2r1 = r2 and L1 = 2L2
Radiation Activity: Fermium-253 has a half-life of 3.00 days. A sample of fermium has 3.88 × 106 nuclei. What is the initial activity of this sample?
A. 10.4 Bq B. 10.4 kBq C. 12.9 Bq D. 12.9 kBq
A car travels in a due northerly direction at a speed of 55 km/h. The traces of rain on the side windows of the car make an angle of 60 degrees with respect to the horizontal. If the rain is falling vertically with respect to the Earth, what is the speed of the rain with respect to the Earth?
A. 48 km/h B. 95 km/h C. 58 km/h D. 32 km/h E. 80 km/h