HELP ASAP PLEASE Comparing the types and amounts of EM radiation in an object could help scientists determine an object's what? structure age chemical composition all of the above are correct​

A2 kg ball travellng to the right with a speed of 4 m/s collidees with a 5 kg ball traveling to the left with a speed of 3 m/s. take right to be the positive direction. what is the total momentum of the two balls before they collide? what is the total momentum of the two balls after they collide?

You can watch static electricity in action by rubbing an inflated balloon against your hair. your hair will actually stand on its end! it does this because each hair becomes charged, and they all repel one another.

Engines for propeller-driven aircraft are limited in their maximum rotational speed by the fact that the tip speed of the propeller must not approach the speed of sound in air (mach i). taking 6 ft as a typical diameter for a propeller of a light airplane and 1100 fils as the speed of sound, find the upper limit on the rpm (revolutions per minute) of the propeller shaft.