Question

1. a soccer ball is moving horizontally at a speed of +2.4 m/s. it then undergoes a constant acceleration. after 6 s, the ball is moving at +1.6 m/s. what is the balls displacement? (+12 m)

Explanation:

Step1: Find the acceleration

Use the formula $a=\frac{v - u}{t}$, where $u = 2.4$ m/s, $v = 1.6$ m/s and $t = 6$ s.
$a=\frac{1.6 - 2.4}{6}=\frac{- 0.8}{6}=-\frac{2}{15}$ m/s²

Step2: Find the displacement

Use the formula $s=ut+\frac{1}{2}at^{2}$, substituting $u = 2.4$ m/s, $a=-\frac{2}{15}$ m/s² and $t = 6$ s.
$s=(2.4\times6)+\frac{1}{2}\times(-\frac{2}{15})\times6^{2}$
$=14.4-\frac{1}{2}\times\frac{2}{15}\times36$
$=14.4 - 2.4$
$=12$ m

Answer:

$12$ m