A speedboat increases in speed from 20 m/s to 30 m/s in a distance of 200m. Find (a) the magnitude of its acceleration and (b) the time it takes the boat to travel this distance.

(a) (I am not sure what the magnitude is)
(b) 200m x s/30m = 6.67s (is this correct?)

2 answers

It's a bit easier if you do (b) first.

(b) The average speed will be 25 m/s, and the time required to travel that distance will be 200 m/(average speed) = 200m/(25 m/s) = 8 s
(a) The magnitude of the acceleration is (speed change)/time = (10 m/s)/8 s = 1.25 m/s^2

You could also have used the formula
2aX = V2^2 - V1^2 = 900 - 400 = 500, and solved for the acceleration
a = 500/(2X) = (500 m^2/s^2)/400 m. You'd get the same answer; however, that formula is a bit harder to remember.
1,25
Similar Questions
    1. answers icon 1 answer
    1. answers icon 1 answer
  1. A speedboat increases in speed from 19 m/sto 31.4 m/s in a distance 193 m. Find the magnitude of its acceleration. Answer in
    1. answers icon 0 answers
  2. 016 (part 1 of 2) 10.0 pointsA speedboat increases in speed from 17.9 m/s to 31.8 m/s in a distance 188 m. Find the magnitude of
    1. answers icon 1 answer
more similar questions