27. When light from the Sun is absorbed by a dark surface, the surface re-emits radiation that has (A) a shorter wavelength and lower frequency. (B) a longer wavelength and lower frequency. (C) a shorter wavelength and higher frequency. (D) a longer wavelength and higher frequency. 28. Suppose two light bulbs are designed to draw 100 W and 60 W of power when operated at the same household voltage. Which bulb has the higher resistance? (A) The 100-W bulb. (B) The 60-W bulb. (C) It’s impossible to say without knowing the current. 29. In which of the following materials does sound travel the fastest at room temperature? (A) Air. (B) Helium gas. (C) Sea water. (D) Steel. 30. Suppose the temperature in a room remains constant at 20 ◦C as time passes. An object with initial temperature 80 ◦C is placed in the room. If its temperature drops by 30 ◦C in the first hour, how much further will it drop in the second hour? Assume Newton’s Law of Cooling describes the process. (A) 60 ◦C. (B) 30 ◦C (C) 15 ◦C (D) 5 ◦C
27. When light from the Sun is absorbed by a dark surface, the surface re-emits
(A) a shorter wavelength and lower frequency.
(B) a longer wavelength and lower frequency.
(C) a shorter wavelength and higher frequency.
(D) a longer wavelength and higher frequency.
28. Suppose two light bulbs are designed to draw 100 W and 60 W of power when operated at the same household voltage. Which bulb has the higher resistance?
(A) The 100-W bulb.
(B) The 60-W bulb.
(C) It’s impossible to say without knowing the current.
29. In which of the following materials does sound travel the fastest at room temperature?
(A) Air.
(B) Helium gas.
(C) Sea water.
(D) Steel.
30. Suppose the temperature in a room remains constant at 20 ◦C as time passes. An object with initial temperature 80 ◦C is placed in the room. If its temperature drops by 30 ◦C in the first hour, how much further will it drop in the second hour? Assume Newton’s Law of Cooling describes the process.
(A) 60 ◦C.
(B) 30 ◦C
(C) 15 ◦C
(D) 5 ◦C
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
