EASY HELPPP Resistance and resistivity are related by a:

factor that is dependent on the length of the material
factor that is dependent on the area of the material
proportionality constant dependent on the identity of the material
proportionality constant dependent on the source of the material

prolly a beacuse the momentuem the car has increases while going down hill

graph slopes whilst gas cools, then it is flat whilst conensation to liquid happens, the coolong liquid then graphs as a slope when it solidifies graph is flat

latent heat

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