Question

A reconnaissance plane flies 605 km away from

its base at 284 m/s, then flies back to its base
at 426 m/s.
What is its average speed?
Answer in units of m/s.

Answer 1

`v_(avg)  =` 355 m/s

Step-by-step explanation:

Distance = 605 km

Initial speed =
`v_(i)` = 284 m/s

Final velocity =
`v_(f)` = 426 m/s

Average speed = ?

There is two method two find average speed. In first method, using 3rd equation of motion, we find acceleration.

`2as = v_(f)^(2)+v_(i)^(2)`

Then using first equation of motion, we find time

`v_(f) = v_(i)+at`

Then using the formula of average velocity, we find average velocity

`v_(avg)=(total-distance)/(total-time)`

Second method is very simple

`v_(avg)=(v_(f)+v_(i) )/(2)`

`v_(avg)=(426+284)/(2)`

`v_(avg)  =` 355 m/s