Question

6. An aircraft is travelling along a runway at a velocity of 25m/s. It accelerates at a rate of 4.4m/s for a

distance of 750m before taking off. Calculate its take-off speed.​

Answer 1

85m/s

Step-by-step explanation:

i just did this on a test

Answer 2

85 m/s

Step-by-step explanation:

The equation for velocity v and a uniform acceleration a:

`v=at+v_0`

This equation has 2 unknown. You need a second equation to solve the problem.

The equation for position x and a uniform acceleration:

`x = (1)/(2)at^2+v_0t+x_0`

This equation has only one unknown, the time t. You can combine both equations and eliminate time.

`x-x_0=((v-v_0)^2)/(2a)+v_0((v-v_0))/(a) =(v^2-2vv_0+v_0^2+2vv_0-2v_0^2)/(2a)=(v^2-v_0^2)/(2a)`

Solving for v:

`v=√(2a(x-x_0)+v_0^2)`