QUESTION 4 A ball is dropped from a tall building. What will its speed be after it has been falling for a time of 4.3 s, in units of m/s? Assume that air resist

Réponse:

Let (Oz) be the vertical axis (pointing down) with O the point from where you drop the ball.

Newton's second law gives that a=g and if you integrate relative to the time you get v=gt + C.

v(0)=C=0 so v=gt and if you calculate for t=4.3s and g=9.1m/s^2, you get v=39.13m/s.