What are the first three harmonics of a note produced on a 0.31 m long violin string if the waves on this string have a speed of 274.4 M/s

This is the substance(s) formed in a chemical reaction.

Could we see a galaxy that is 20 billion light-years away?

Abumper car with a mass of 250 kg is traveling at a speed of 4 m/s. this bumper car collides and sticks to a second bumper car with a mass of 250 kg, which is initially at rest. what is the final speed of these two bumper cars after the collision, assuming they remain stuck together?