What two factors affect the strength of a gravitational attraction? How does each effect the strength

What is a carrier wave and how does it affect what you hear on the radio

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value