At what speed does a 1600 kg compact car have the same kinetic energy as a 20000 kg truck going 23 km/h

Frank just graduated from eighth grade. assuming exactly four years from now he will graduate from high school how many seconds does he have until his high school graduation

Macy always thought there were only a few hair colors blonde brown and black however when she actually began looking around she saw varying shades of these hair color what is a possible reason for so many different hair colors

What is the difference between mass density and weight density?