5. It takes you 5 hours to complete a 375-kilometer trip. What was your average speed on this trip?

the average speed on this trip is 75 km/h

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me