Question

question
type the correct answer in the box.
at the start of a race, a runner’s velocity changes from 0 to 4.0 m/s. it takes him 2 seconds to speed up. his acceleration is m/s².

Explanation:

Step1: Recall the acceleration formula

Acceleration \( a \) is calculated by the change in velocity \( \Delta v \) divided by the time taken \( \Delta t \), so the formula is \( a=\frac{\Delta v}{\Delta t} \).

Step2: Identify the values of \( \Delta v \) and \( \Delta t \)

The initial velocity \( v_i = 0\space m/s \), the final velocity \( v_f = 4.0\space m/s \), so the change in velocity \( \Delta v=v_f - v_i=4.0 - 0 = 4.0\space m/s \). The time taken \( \Delta t = 2\space s \).

Step3: Calculate the acceleration

Substitute the values into the formula: \( a=\frac{4.0}{2}=2.0\space m/s^2 \).

Answer:

\( 2.0 \)