Justin designed an experiment to find out how running up bleachers affects his heart rate. First he records his resting heart rate and then runs up the bleachers 10 times. Each time he reaches the top, he records his heartrate then rests 20 minutes. Which is involved in Justin's experiment?

Ahypothesis is? close agreement by competent observers of observations of the same phenomena. a guess that has been tested over and over again and always found to be true. an educated guess that has yet to be proven by experiment. the long side of a right triangle. a synthesis of a large collection of information that includes guesses.

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?

What kind of simple machine is a catapult?