Question

a toy race car zooms across the ground with an acceleration of 1.8 m/s^2. after 3 seconds it has a final velocity of 12.2 m/s, what is the toy cars initial velocity?
a= (vf - vi)/t
(1 point)
22.8 m/s
6.8 m/s
9.8 m/s
1.8 m/s

Explanation:

Step1: Rearrange the acceleration formula

We start with $a=\frac{V_f - V_i}{t}$, and we want to solve for $V_i$. Multiply both sides by $t$: $at=V_f - V_i$. Then, rearrange to get $V_i = V_f - at$.

Step2: Substitute the given values

We know that $a = 1.8\ m/s^2$, $t = 3\ s$, and $V_f=12.2\ m/s$. Substitute these into the formula: $V_i=12.2-1.8\times3$.

Step3: Calculate the result

First, calculate $1.8\times3 = 5.4$. Then, $V_i=12.2 - 5.4=6.8\ m/s$.

Answer:

B. 6.8 m/s