Which of the following astronomical objects emit radiation mostly at non-visible wavelengths?
A. cold interstellar gas clouds
B. dust clouds in space
C. hot gas surrounding black holes
D. All of these choices are correct.
Answer: D
You might also like to view...
A car starts from rest and reaches 20 m/s in 5 seconds. The average acceleration of the car is
A. 1.0 m/s2. B. zero m/s2. C. 4.0 m/s2. D. 10.0 m/s2. E. 2.0 m/s2.
The biggest obstacle to life being present in the atmospheres of Jupiter and Saturn is the
A) absence of liquid water in their atmospheres B) high levels of solar radiation that would destroy any biological molecules C) strong vertical wind speeds that would rapidly carry organisms into the hot interior where they would be destroyed D) very low temperatures at the tops of the clouds where water would not be liquid
The electric field at the surface of a positively charged conductor has a direction characterized by which of the following?
a. perpendicular outward and away from the charge b. at a 45° angle to the surface c. tangent to the surface d. perpendicular inward toward the charge
In the figure, two wooden blocks each of 0.30 kg mass are connected by a string that passes over a very light frictionless pulley. One block slides on a horizontal table, while the other hangs suspended by the string, as shown in the figure
At time t = 0, the suspended block is 0.80 m over the floor, and the blocks are released from rest. After 2.5 s, the suspended block reaches the floor. What is the coefficient of kinetic friction between the table and the sliding block? A) 0.35 B) 0.52 C) 0.84 D) 0.65 E) 0.95