Question

bus at a stoplight
a bus speeds up from 0 km/h to 54 km/h in 9 seconds. first, convert speed to m/s, then calculate the acceleration.
$a=\frac{v_f - v_i}{t}=$

Explanation:

Step1: Convert final speed to m/s

We know that $1\ km = 1000\ m$ and $1\ h=3600\ s$. So, to convert $54\ km/h$ to $m/s$, we use the conversion factor: $v_f = 54\times\frac{1000}{3600}= 15\ m/s$. The initial speed $v_i = 0\ km/h=0\ m/s$ and time $t = 9\ s$.

Step2: Calculate acceleration

The formula for acceleration is $a=\frac{v_f - v_i}{t}$. Substitute $v_f = 15\ m/s$, $v_i = 0\ m/s$ and $t = 9\ s$ into the formula: $a=\frac{15 - 0}{9}=\frac{15}{9}=\frac{5}{3}\approx1.67\ m/s^{2}$.

Answer:

$\frac{5}{3}\ m/s^{2}$ or approximately $1.67\ m/s^{2}$