Question

choose the equation that helps solve the following problem most easily. kristen drops out of school to pursue a career as a stunt person in hollywood. her first gig was to ride a rocket - powered sled that accelerated to a speed of 444 m/s in 1.83 seconds, then what distance did she travel? (hint: $v_0 = v$)
$d = v_0t+\frac{1}{2}at^2$ (hint: $v_0 = v$)
$v_f^2 = v_0^2 + 2ad$ (hint: $v_0 = v$)
$d=\frac{v_0 + v_f}{2}cdot t$ (hint: $v_0 = v$)
$v_f = v_0+at$ (hint: $v_0 = v$)

Explanation:

Step1: Identify given values

We know $v_f = 444$ m/s, $t=1.83$ s and since $v_0 = v_f$ (given hint), the motion is at a constant - final speed.

Step2: Select the appropriate equation

The equation $d=\frac{v_0 + v_f}{2}\cdot t$ is most suitable. When $v_0 = v_f$, it simplifies to $d = v_f\cdot t$. The other equations involve acceleration $a$ which is not needed here as the motion is at a constant speed (implied by $v_0 = v_f$).

Answer:

$d=\frac{v_0 + v_f}{2}\cdot t$