When must scientific theories be changed? A. When one experiment shows a surprising result
B. When a new government is elected
O C. When enough evidence contradicts earlier ideas
O D. When an old scientist dies

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Contains chemical energy. a. heat b. light c. natural gas

What is the magnitude of the gravitational force acting on the earth due to the sun?