Aprediction

a. is not a strategy used in a scientific investigation.
b. is the final step in a scientific investigation.
c. is an optional step in a scientific investigation.
d. is a necessary step in a scientific investigation.

Which of the following is considered to be a vector?               a.  temperature    b.  velocity    c.  time    d.  mass

Aplanet of mass m 6.75 x 1024 kg is orbiting in a circular path a star of mass m 2.75 x 1029 kg. the radius of the orbit is r 8.05 x107 km. what is the orbital period (in earth days) of the planet tplanet?

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?