Question

fall 2025 physics a wwva introduction to waves solving using the speed of sound if a storm is 7.5 kilometers away, how much time is expected between observations of lightning and thunder? round your answer to one decimal place. seconds

Explanation:

Step1: Recall the speed of sound

The speed of sound in air is approximately \( v = 343\space m/s \) (at room temperature and standard pressure). First, we need to convert the distance from kilometers to meters. Since \( 1\space km = 1000\space m \), the distance \( d = 7.5\space km = 7.5\times1000 = 7500\space m \).

Step2: Use the formula for time

The formula relating speed (\( v \)), distance (\( d \)), and time (\( t \)) is \( t=\frac{d}{v} \). Substituting the values of \( d = 7500\space m \) and \( v = 343\space m/s \) into the formula, we get \( t=\frac{7500}{343} \).

Step3: Calculate the time

Calculating \( \frac{7500}{343}\approx21.9 \) (rounded to one decimal place).

Answer:

\( 21.9 \)