# [SOLVED] Instantaneous velocity and Average velocity

• Feb 20th 2010, 09:44 AM
[SOLVED] Instantaneous velocity and Average velocity
An airplane maintains a constant acceleration of 4.0m/s^2 [E] as it speeds up from 16m/s [E] to 28m/s [E].

a) What is the average velocity?

22m/s [E]

b) How long does the airplane accelerate?

3s

c) When is the instantaneous velocity equal to the average velocity for the interval?

This is the question I need help on. I know a time is required for this question, though is the instantaneous velocity required too? If it is, how would I solve for it?
• Feb 20th 2010, 09:47 AM
e^(i*pi)
Quote:

An airplane maintains a constant acceleration of 4.0m/s^2 [E] as it speeds up from 16m/s [E] to 28m/s [E].

a) What is the average velocity?

22m/s [E]

b) How long does the airplane accelerate?

3s

c) When is the instantaneous velocity equal to the average velocity for the interval?

This is the question I need help on. I know a time is required for this question, though is the instantaneous velocity required too? If it is, how would I solve for it?

Use Newton's Laws of Motion

v = u+at

Set v equal to the average velocity, u to the initial velocity and a to the acceleration

$22 = 16+4t$

Solve for t.
• Feb 20th 2010, 10:01 AM