Why can gamma rays pass through or penetrate solids?
a. gamma rays have low mass.
b. gamma rays have high mass.
c. gamma rays have low velocity.
d. gamma rays have high velocity.

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of