9. Hikers at the bottom of a canyon are facing towards the canyon wall 280.5 meters away. Given that the speed of sound in air is 340 m/s, how long after they shout will they hear their echo?

The time it takes for the hikers to hear their echo after they shout is 1.65 seconds

Explanation:

The given parameters are;

The distance from the canyon wall to the hikers = 280.5 meters

The speed of sound in air = 340 m/s

Therefore, we have;

Distance traveled by the sound of shouting = 280.5 meters

Distance traveled by the reflection (echo) of the sound of shouting = 280.5 meters

Total distance traveled by the sound to reach back to the hikers = 280.5 + 280.5 = 561 meters

Time, t, for the sound to reach the hikers = Distance traveled by the sound/(The speed of sound in air)

t = 561 m/(340 m/s) = 1.65 seconds.

dang that balls went far

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west