How many days a week should children and teenagers get 60 minutes of physical activity? two days a week three days a week four days a week five days a week

If a person has a bad pain in their back, specifically lower back a bit above the hip, what should they do besides going to the doctor? what remedies could they use?

Can you receive a shock severe enough to prevent you from releasing the wire from an ordinary outlet with dry hands?

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?