Ahiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. she hears the echo 2.9 s after shouting. the speed of sound in air is 343 m/s. determine the length of the lake.

497.35 m.

Explanation:

Echo: This is the sound heard after the reflection of sound wave on a plane surface.

v = 2x/t Equation 1

Where v = speed of sound in air, x = length of the lake, t = time taken to hear the echo.

Making x the subject of the equation,

x = vt/2 Equation 2

Given: v = 343 m/s, t = 2.9 s.

Substitute into equation 2

x = 343×2.9/2

x = 497.35 m

Thus the length of the lake  = 497.35 m.

yeet youwelcome broo

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.