A person wants to find the width of the lake by shouting and listening for the echo from the far side. If his echo returns after 2 seconds how wide is the lake? (Velocity of sound is 340 m/sec)

The width of the lake is 340 m

Explanation:

Constant Velocity Motion

It occurs when an object travels the same distance every equal interval. For example, if it travels 5 m in one second, then 10 m in two seconds, etc., it has a constant velocity.

The speed of the sound is assumed as v=340 m/s and the person measures the time that a sound goes and comes from the edge of a lake as t=2 seconds. The distance it travels is:

d = v.t

d = 340 m/s * 2 s

d = 680 m

But that distance is twice the width of the lake, the real measured width is 680 m / 2 = 340 m

The width of the lake is 340 m

its c i just checked it