Acontrol is a
a. variable that changes during an experiment.
b. standard for comparison.
c. type of dependent variable.
d. type of experiment.

This is how zirconium appears in the periodic table. rounded to the nearest whole number, how many electrons are in an atom of zirconium?

Work = force × a. work b. energy c. distance d. momentum

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?