John flies from atlanta, georgia to san francisco, california. it takes 5.6 hours to travel 2100 miles against the head wind. at the same time, debby flies from san francisco to atlanta. her plane travels with the same average airspeed, but with a tail wind, and her flight takes only 4.8 hours. write a system of equations that relates time, airspeed, and wind speed to distance for each traveler. solve the system to find the airspeed. a. 406.25 mi/h c. 519 mi/h b. 408.45 mi/h d. 480 mi/h

John :
distance = 2100 mi ; time = 5.6 hrs ; rate = d/t = 2100/5.6 = 375 mph

Debby:
distance = 2100 mi ; time = 4.8 hrs ; rate = d/t = 2100/4.8 = 437.5 mph

Let air speed be a and wind speed be w; then:
a+w=437.5 mph
a-w=375 mph

Solve the system to find the air speed.
Add the two equations:

a+w=437.5

a-w=375

becomes
2a = 812.5

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

fwms@lil_ben06

step-by-step explanation: