Question

An aircraft has a landing velocity of 50 ms-1 and decelerates uniformly at 10 ms-2Calculate:
(a) the time taken to reach 15 ms-1
(b) the distance travelled during this time
(c) the velocity of the car when it was 100 m from the start point

Answer 1

a. t = (Vf - Vo) / a,
t = (15 - 50) / -10 = 3.5s.

b. d = Vo*t + 0.5a*t^2,
d = 50*3.5 + (-5)(3.5)^2 = 113.75m.

c. Vf^2 = Vo^2 + 2a*d,
Vf^2 = (50)^2 + (-20)100 = 500,
Vf = 22.36m/s.