Question

An object moves with constant acceleration 4.00 m/s^2 and over a time interval reaches a final velocity of 12.0 m/s.

a) If its initial velocity is -6.00 m/s, what is its displacement during the time interval.

b) What is the total distance it travels during the time interval in part b?

Answer 1

a) We can use the equation of motion:
2as = v² - u²
s = (12² - (-6)²) / 2 x 4
s = 13.5 m

b) We calculate the time over which this displacement occurred using:
v = u + at
t = (12 - -6)/4
t = 4.5 seconds
Assuming the average speed equal to:
(12 + 6) /2 = 9 m/s
average speed = total distance/total time
total distance = 9 x 4.5
= 40.5 m