posted by axel .
A car travels along a highway with a velocity of 24 m/s, west. The car exits the highway and 4.0 s later,
its instantaneous velocity is 16 m/s, 45o north of west. What is the magnitude of the average acceleration
of the car during the five-second interval?
Is it a really five second interval? You only provide information for a four second interval. I'd need to know what the car did during the last second.
Anyway, calculate the vector difference in the car velocities (final minus initial) , and divide the result by the time interval, whatever it is.