Question

Help! Medal+Fan!!

Answer 1

What is the average acceleration of a jet ski that goes from rest to 10 m/s west in 4 s? Take the direction west to be positive, and east to be negative.

A.
2.5 m/s2

B.
-2.5 m/s2

C.
0.4 m/s2

D.
-0.4 m/s2

Answer 2

average acceleration = change in velocity / time taken
so average acceleration = ( 10 - 0 ) / 4 = 2.5 m/s^2

Answer 3

positive since final velocity is 10m/s to the west, and initially at rest.