Do astronomers use ground-based X-ray telescopes?
A. No, because no astronomical objects emit X-rays.
B. No, because X-rays cannot get through Earth's atmosphere.
C. Yes, because they can penetrate gas clouds.
D. No, because astronomers have not yet devised detectors for X-rays.
Answer: B
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Two identical balls are at rest side by side at the bottom of a hill. Some time after ball A is kicked up the hill, ball B is given a kick up the hill. Ball A is headed downhill when it passes ball B headed up the hill. At the instant when ball A passes ball B,
a. it has the same position and velocity as ball B. b. it has the same position and acceleration as ball B. c. it has the same velocity and acceleration as ball B. d. it has the same displacement and velocity as ball B. e. it has the same position, displacement and velocity as ball B.
Compound Microscope: The objective lens of a microscope has a focal length of 2.4 mm and the eyepiece has an angular magnification of 15. The object is positioned 0.060 mm beyond the focal point of the objective. The focal point of the eyepiece is positioned at the real image formed by the objective. The near point of the microscope user is at 25 cm. The magnitude of the overall magnification of the microscope is closest to
A. 400. B. 450. C. 500. D. 550. E. 600.
Determine the energy stored by C4 when C1 = 20 ?F, C2 = 10 ?F, C3 = 14 ?F, C4 = 30 ?F, and V0 = 45 V.
A. 3.8 mJ B. 2.7 mJ C. 3.2 mJ D. 2.2 mJ E. 8.1 mJ
A 4.0-?C charge is situated at the origin of an xy-coordinate system. What is the potential difference between a point x = 4.0 m and y = -4.0 m because of this charge?
A) 18 × 103 V B) -18 × 103 V C) 0 V D) 36 × 103 V E) -36 × 103 V