Question

I need help with this word problem please ​

Answer 1

Answer:

-60 m/s²

Step-by-step explanation:

We are not given the velocity of the plane at landing but we are given velocities at two time periods

V₅, the velocity of the plane 5 seconds after landing is 110 m/s

Plugging this into the velocity equation we get

$\bold{v_5 = a.5 + v_0 = 5a + v_0}$                (1)

Similarly

$\bold{v_{15} = a.15 + v_0 = 15a + v_0}$           (2)

Subtract (1) from$v_{15} - v_5 = (15a + v_0) - (5a + v_0) = (15a-5a) + (v_0-v_0) = 10a$

Therefore $a = \frac{v_{15} - v_5}{10}$

Given $v_{15}= 50 m/s \textrm{ and } v_5 = 110m/s$

this evaluates to

$a = (50-110)/10 =$  -60 m/s²

The negative value is because the plane is actually decelerating which is a negative number