Question

An aircraft, traveling northward, lands on a runway with a speed of 79 m/s. Once it touches down, it slows to 6.0 m/s over 785 m of runway. What is the average acceleration (magnitude and direction) of the plane during landing (in m/s2)? Take the positive direction to be northward.

Answer 1

Answer:

$-3.95m/s^2$, South

Explanation:

We are given that

Initial speed of aircraft,u=79 m/s

Final speed of aircraft,v=6 m/s

Distance,s=785 m

$v^2-u^2=2as$

Substitute the values

$(6)^2-(79)^2=2a(785)$

$36-6241=1570a$

$-6205=1570a$

$a=-\frac{6205}{1570}=-3.95m/s^2$

Where negative sign indicates that the direction of acceleration is opposite to direction of motion.

Therefore, the direction of acceleration is south.