Question

Sound travels at 340 meters per second in air.

(a) Find the distance traveled by sound in air in 7 seconds. Give your answer in kilometers.

In 7 seconds, sound travels ? kilometers.

(b) A boy clapped his hands near a cliff. He could hear the echo of his claps 3 seconds later. Find his distance from the cliff. (Remember an echo has to travel the entire distance and then back so you will need to divide by 2 before you give your final answer).

The boy is ? meters from the cliff.

Answer 1

In 7 seconds, sound travels 2.38 kilometers in air. The boy is 510 meters from the cliff.

Step-by-step explanation:

(a) To find the distance traveled by sound in 7 seconds, we can use the formula: distance = speed x time. The speed of sound in air is given as 340 meters per second. So, the distance traveled by sound in 7 seconds can be calculated as: distance = 340 m/s x 7 s = 2380 meters. To convert this distance to kilometers, we divide by 1000: distance = 2380 meters ÷ 1000 = 2.38 kilometers.

(b) To find the distance of the boy from the cliff, we need to consider the time it took for the sound to travel to the cliff and back as an echo. The boy heard the echo 3 seconds later, which means the sound traveled to the cliff and back in 3 seconds. Let's divide this time by 2 to account for the round trip: time for one-way trip = 3 s ÷ 2 = 1.5 seconds. Now, we can use the formula: distance = speed x time. The speed of sound is still 340 meters per second. So, the distance of the boy from the cliff can be calculated as: distance = 340 m/s x 1.5 s = 510 meters.

Answer 2

Answer: A) 2.38 kilometers B) 510 meters

Step-by-step explanation:

A) 340 meters times 7 seconds = 2380 meters/1000 meters which is 2.38 kilometers

B) 340 meters per second times 3 seconds= 1020 meters/2= 510 meters