A ruby laser beam (? = 694.3 nm) is sent outwards from a 2.7-m diameter telescope to the moon, 384,000 km away. What is the radius of the big red spot on the moon?
a. 500 m
b. 250 m
c. 120 m
d. 1.0 km
e. 2.7 km
c
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Which of the following describes a velocity (as opposed to a speed)?
A) 20 kilometers per hour, headed north B) 300,000 kilometers per second C) 9.8 meters per second squared (m/s2) D) 15 newtons E) 5 light-years
About what percentage of Hubble Deep Field (HDF) galaxies do astronomers find are irregular?
A: 5%. B: 25%. C: 50%. D: 70%. E: 90%.
The exterior of a supersonic airplane is made of aluminum, which has a coefficient of linear expansion of 24 × 10-6 K-1. At 15°C, the plane measures 62.1 m in length
When the plane is in flight, friction with the air increases the temperature of the exterior skin to 200°C. What is the change in the length of the outer skin of the plane? A) 32 cm B) 20 cm C) 36 cm D) 24 cm E) 28 cm
Frost wedging is a form of
a) terminal erosion. b) physical weathering. c) chemical weathering. d) slow mass wasting.