Darius' boat sails into the harbor with a speed of 80m/s. After 20 seconds, Darius' boat has come to a stop at the dock. What is his boat's acceleration?

The boat's acceleration is 4 m/s²

Explanation:

This question seeks to test the knowledge of acceleration and how to calculate acceleration when the speed is provided. Hence, the formula for acceleration would be used here.

Acceleration (m/s²) = speed (in m/s) ÷ time (in seconds)

Acceleration = 80 m/s ÷ 20 secs

Acceleration = 4 m/s² or 4 ms⁻²

The boat's acceleration is 4 m/s²

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)