Why is it surprising that spiral arms are stable structures, lasting billions of years?
a. Differential rotation should tear the arms apart
b. Gas and dust clouds should run out of material to make young stars.
c. Supernova explosions should disrupt the arms.
d. Globular clusters are continuously passing through the arms.
e. Gravity should pull the arms down into the center of the galaxy.
a
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A 4.00 kg object is moving at 5.00 m/s EAST. It strikes a 6.00 kg that is at rest. The objects have an elastic collision. The velocity of 4.00 kg object after the collision is in the SOUTHWEST direction. The velocity of the 6.00 kg object after the collision is
A. 2.38 m/s. B. 3.02 m/s. C. 3.51 m/s. D. 4.06 m/s. E. 5.22 m/s.
An RGB color system can produce more than 16.7 million possible colors.
Answer the following statement true (T) or false (F)
The force on your left palm is __________ the force on your right palm
a. 1/4 b. 1/2 c. equal to d. 2 times e. 4 times
A heat engine takes in 500 J of energy from the hot reservoir in one cycle while performing 100 J of work. The amount of heat transferred to the cold reservoir in the same time is
A. 400 J. B. zero. C. 500 J. D. 300 J. E. 200 J.