Optics of the Eye: A person's eye lens is 2.8 cm from the retina, and his near point is at 25 cm. What must be the focal length of his eye lens so that an object at the far point of the eye will focus on the retina?
A. -2.8 cm
B. 2.8 cm
C. -2.4 cm
D. 2.4 cm
E. 2.2 cm
Answer: B
You might also like to view...
What is the phase angle in a series RLC circuit at resonance?
1.180° 2.90° 3.0 4.-90° 5.None of these answers is necessarily correct.
Suppose a mass is attached to the end of a horizontal oscillating spring of spring constant. Choose the answer that will double the frequency of oscillation.
A. Quadruple the mass, or quadruple the spring constant. B. Divide the mass by four, or quadruple the spring constant C. Divide the mass by two, or double the spring constant D. Divide the mass by 2, or multiply the spring constant by 2
What theoryexplains the movement of the continents on Earth's surface?
a. continental spreading b. continental drift c. continental tectonics d. continental rifting e. continental rise
A camper carries her drinks in an ice chest made of styrofoam. The chest is 40 cm × 45 cm × 70 cm, and the walls and lid are 2.5 cm thick
The contents of the chest are ice, water, cans of soft drinks, and other food, all of which are in thermal equilibrium with the ice water. The temperature just outside the ice chest is 35°C. What is the rate of heat flow through the walls of the box? The thermal conductivity of styrofoam is 0.010 W/(m•K). A) 14 W B) 16 W C) 18 W D) 20 W E) 22 W