The power of a lens is 4.0 diopters and its diameter is 5.0 cm. What is the focal length of this lens?
A) 25 cm
B) 55 cm
C) 10 cm
D) 0.25 cm
E) 2.5 cm
A
You might also like to view...
Velocity Addition: From the Earth, the Earthlings see the Enterprise approaching from the west at 0.800c and the Klingons approaching from the east at 0.900c. What speed, in terms of the speed of light, does the crew of the Enterprise measure for the Klingon ship?
Fill in the blank(s) with the appropriate word(s).
Starburst galaxies produce most of their light in the infrared
Indicate whether the statement is true or false
A satellite is placed in a geosynchronous orbit. In this equatorial orbit with a period of 24 hours, the satellite hovers over one point on the equator. Which statement is true for a satellite in such an orbit?
A. There is no gravitational force on the satellite. B. There is no acceleration toward the center of the Earth. C. The satellite is in a state of free fall toward the Earth. D. There is a tangential force that helps the satellite keep up with the rotation of the Earth. E. The force toward the center of the Earth is balanced by a force away from the center of the Earth.
The second law of thermodynamics implies that
A) non-thermal forms of energy cannot be entirely converted into thermal forms of energy. B) thermal energy cannot be entirely converted into non-thermal forms of energy. C) from the microscopic point of view, thermal energy is just kinetic energy of individual atoms and molecules. D) in physical process in which heat is produced, the total amount of energy is reduced by an amount equal to amount of heat produced. E) in every physical process, the total amount of energy must remain unchanged.