Why are essential workers important to our society

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the dependent variable in galileo's experiment?

Second hand smoke can be almost as harmful as smoking. true or false?

Muscles and joints that can move through their full range of motion are more powerful, more coordinated, and less likely to be injured.