A person with normal eyesight uses a converging lens of focal length 10 cm. He holds the lens close to his eyes to finish an engraving job
(a) What is the magnifying power of the lens?
(b) At what distance from the job he must hold the lens?
(a) 3.5
(b) 7.1 cm
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The y-component of the electric field of an electromagnetic wave traveling in the +x direction through vacuum obeys the equation Ey = (375 N/C) cos[kx - (2.20 × 1014 rad/s)t]. (c = 3.0 × 108 m/s)
(a) What is the largest that the x-component of the wave can be? (b) What is the largest that the z-component of the wave can be? What will be an ideal response?
When a fixed amount of ideal gas goes through an isochoric process,
A) its internal (thermal) energy does not change. B) the gas does no work. C) no heat enters or leaves the gas. D) its temperature must increase. E) its pressure must increase.
When bringing water to a boil in the mountains, the time needed to reach the boiling point is
A) less than at sea level. B) more than at sea level. C) the same as at sea level.
Satellite Motion: Asteroid Ida was photographed by the Galileo spacecraft in 1993, and the photograph revealed that the asteroid has a small moon, which has been named Dactyl. From the dimensions of Ida and its general features, one can estimate the mass of Ida to be 4.5 × 1016 kg, and the distance between Dactyl and Ida is approximately 90 km. Assuming a circular orbit, what would be the orbital speed of Dactyl? (G = 6.67 × 10-11 N ? m2/kg2)
A. 5.8 m/s B. 11 m/s C. 2.3 m/s D. 2.9 m/s E. 30 m/s