After touchdown a fighter jet passes a marker on the runway at an instantaneous speed of 100 m/s and constant negative acceleration of -15 m/s2. After slowing down to 25 m/s, the pilot suddenly goes to full power to provide a new constant acceleration of 35 m/s2 for a "touch and go" takeoff. How far from the original runway marker does the plane achieve its takeoff speed of 170 m/s?

Respuesta :

Given that,

Deacelectration = -15 m/s²

Negative sign shows the declaration

Slowly speed = 25 m/s

Acceleration = 35 m/s²

Speed = 170 m/s

We need to calculate the time

Using equation of motion

[tex]v=u+at[/tex]

Where, v = final velocity

u = initial velocity

a = acceleration

t = time

Put the value into the formula

[tex]25=0+15\times t[/tex]

[tex]t=\dfrac{25}{15}[/tex]

[tex]t=1.66\ sec[/tex]

We need to calculate the distance from the original runway

Using equation of motion

[tex]s=ut+\dfrac{1}{2}at^2[/tex]

[tex]s=0+\dfrac{1}{2}\times35\times(1.66)^2[/tex]

[tex]s=48.2\ m[/tex]

Hence, The distance from the original runway is 48.2 m.