How much energy is radiated each second by one square meter of a star whose temperature is 10,000 K? s in the Stefan-Boltzmann law is equal to

,



a. 5.67 x 10¹² J

b. 5.67 x 10⁸ J

c. 5.67 x 10⁴ J

d. 300 nm

e. 300,000,000 nm

---

B

Physics & Space Science

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

a. they are formed by material falling into the galaxy. b. they are powered by magnetic fields. c. they are excited by radiation from nearby galaxies. d. they are powered by the rapid rotation of the galaxy. e. they are created by jets from the galaxy emitting where the material is halted.

Calorimetry: If 50 g of lead (of specific heat 0.11 kcal/kg ? C°) at 100°C is put into 75 g of water (of specific heat 1.0 kcal/kg ? C°) at 0°C. What is the final temperature of the mixture?

A. 2.0°C B. 6.8°C C. 25°C D. 50°C

A person with an initial mass of 70 kg climbs a stairway and thereby rises 6.0 m in elevation

By how much does his mass increase by virtue of his increased potential energy? (c = 3.0 × 108 m/s)

The electric field associated with a uniformly charged hollow metallic sphere is the greatest at:

a. the center of the sphere. c. infinity. b. the sphere's outer surface. d. the sphere's inner surface.