1-a car speeding up at a green light would be speed. 2-a car slowing down at a red light would be speed.
3- a car turning would change , and is still accelerating, even if the speed is constant.

Abaseball picther can throw a ball at about 90 miles per hour, v = 40 m/s, on solid rock ground. we now put him into space. when he throws the ball, which weighs mb = 0.15 kg moves away from himat the same speed. how long does it take the ball thrown in space to travel the 30 meters to the batter? he weighs mp = 100kg

Suppose you increase your walking speed from 7 m/s to 13 m/s in a period of 2 s. what is your acceleration?

If y gets smaller as x gets bigger and y have an relationship?