The beginning of every workout should start with

Stretching. Without stretch before a workout, you can overdo your body, tear muscles and not be loose enough to do whatever workout you are planning to do; (dance, swimming, weight lifting, etc.) Stretching also clears the mind and gives a yoga like status to your body, giving you a good mindset while working out. It also gets your blood pumping and your muscles looser. Hope this helps! :)

b. false

explanation:

suppose a rock in free fall is dropped off a cliff. after falling for 5 seconds, its speed would not be 100 m/s.