Is there any book for physics.​

In all trials, the magnitude of the final velocity for g1 + g2 was less than the magnitude of any initial velocity. as mass increased, what happened to the velocity? the velocity decreased. the velocity increased. the velocity of g1 + g2 could not be measured. the velocity was not affected by the mass increase.

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

What is the role of lenses in microscopy?