Question

A boat is initially sailing South at 8 meters per second. After 4 seconds, it is sailing North at 8 meters per second. What was the boat's acceleration?

Question 9 options:

32 m/s

4 m/s^2

0 m/s^2

64 m

Answer 1

Take North to be positive and South to be negative. Then

8 m/s = -8 m/s + a (4 s)

which is the formula for velocity v given initial speed u, acceleration a, and time t,

v = u + a t

Solve for a :

16 m/s = a (4 s)

a = (16 m/s) / (4 s)

a = 4 m/s²

(since it's positive, the acceleration is in the Northern direction)