Acamera gives a proper exposure when set to a shutter speed of 1/250 s at f-number f8.0. the photographer wants to change the shutter speed to 1/1000 s to prevent motion blur. to maintain proper exposure, she should also change the f-number the answer is f4.0.

F4.0

Explanation:

To obtain a shutter speed of 1/1000 s to avoid any blur motion the f-number should be changed to F4.0 because the light intensity goes up by a factor of 2 when the f-number is decreased by the square root of 2.

trig 15.3 cos

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it