Chinook salmon are able to move upstream faster by jumping out of the water periodically; this behavior is called porpoising. suppose a salmon swimming in still water jumps out of the water with a speed of 6.36 m/s at an angle of 45°, sails through the air a distance of l underwater at a speed of 3.58 m/s before beginning another porpoising maneuver. determine the average speed of the fish.

he formula for average speed is (total distance/total time)

the y-component does not matter in this problem. so do 6.26(cos45)=4.43m/s to find the x-component velocity which is constant throughout the duration of the flight. the total distance is 2L because he travels distance L twice.

the total time is ((time in water)+(time out of water)) since you dont have time you must eliminate it. to do this you need (distance)/(time)=velocity

solve for time and you get T=D/V

time in water is L/3.52 and time out of water is L/4.43

add them together and you get (4.43L+3.52L)/(15.59) = 7.95L/15.59

that value is your total time

divide you total distance (2L) by total time (7.95L/15.59) and the Ls cancel out and you get

(31.18)/(7.95) = 3.92 m/s = Average Speed

Explanation: