stuck with physics...plz help?

Question

1. An arresting device on a carrier deck stops a plane in 152m. If the plane is arriving at 66.7 m/s, find the acceleration of the plane. (i only c 3 variables in this prblem and according to the text book u need 4 variables then u can use an equation)...plz help

Answer 1

The equation for determining the acceleration (or in this case the deceleration) is
a = (vf^2 - vi^2)/2s
Since the velocity of the carrier is not given we have to assume that the velocity of the plane is 66.7 m/s relative to the deck. This is vi.vf = 0 because the plane comes to rest on the deck.s = 152 m, so we have what we need to solve:
a = (0 - (66.7)^2)/(2*152
a = - 14.643 m/s^2, which is just under 1.5 G's.