Aiyana drives for 100 s at a rate of 20m/s, then turns around and drives for another 200 s at a rate of 30m/s and completes the rest of her journey at a rate of 90m/s for 100 s. what is her average velocity?

Answer 1

Divide her net distance travelled by 400 seconds.
The answer will depend upon her direction when traveling at 90 m/s. this is not clearly stated.

Answer 2

Displacement = (-20)•100 +30•200+90•100= =13000 m.
Ave velocity = displacement/time taken =
= 13000/400 =32.5 m/s.