Finding velocity with constant, incre., decrea, varying acce

In summary, the question is asking to determine the maximum velocity of a jet based on the characteristics of the fighter (m and A) and the rate of fuel consumption (r(t)). By setting the force of the jet equal to the force of the fighter (F=ma), an equation for acceleration is obtained. Differentiating this equation gives the velocity equation, but further steps are needed to determine the maximum velocity. The problem is similar to one that will be on a test, and a step-by-step explanation would be greatly appreciated.
  • #1
Noah Drakes
19
0

Homework Statement



Force of jet= A(r(t))4/3
A: constant determined by the fighter model in the class being considered and the drag force on the plane
r(t): the rate of fuel consumption as a function of time

Consider 3 possible situations for r(t):

1. when the rate is constant for the duration of the acceleration period
2. when the rate is steadily decreasing for the duration of the acceleration period
3. when the rate decreases at a decreasing rate as the plane accelerates

For each of these you should assume that the rate is initially 500 ffu (fighter fuel units)/min,
and for each it is reasonable to suppose an acceleration period of 10 minutes.

Determine-in terms of the characteristics of the fighter (m and A)- the maximum velocity obtained by the jet

Homework Equations



F=ma

The Attempt at a Solution



I set F=ma equal to Fjet = A(r(t)^4/3. So ma=A(r(t)^4/3 .

Now i solved for "a" to get an equation for acceleration: a=(A(r(t)^4/3)/(m)

Then i differentiated the equation to get velocity : A/m * 3/7 (r(t) ^ (7/3)

confused on how to approach the problem from here. I have a test on wednesday with a problem similar to this problem. It would be immensly helpful if someone solved the problem explaining each step and why.

I am new to this community by the way.
 
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  • #2
i also want to point out i copied the question from someone else's forum, but the work is mine.
 

1. What is velocity?

Velocity is defined as the rate of change of an object's position with respect to time. It is a vector quantity, meaning it has both magnitude (speed) and direction.

2. How do you find velocity with constant acceleration?

To find velocity with constant acceleration, you can use the formula v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. You can also use the formula v^2 = u^2 + 2as, where s is the displacement.

3. How do you find velocity with increasing acceleration?

For a situation with increasing acceleration, you can use the formula v = u + 1/2 (u + v)t, where v is the final velocity, u is the initial velocity, and t is the time. This formula is based on the average acceleration over the time interval.

4. How do you find velocity with decreasing acceleration?

If the acceleration is decreasing, you can use the formula v = u + 1/2 (u - v)t. This formula is similar to the one for increasing acceleration, but with a negative sign in front of the final velocity.

5. Can you find velocity with varying acceleration?

Yes, you can find velocity with varying acceleration by using the instantaneous acceleration at a specific time. This can be calculated by taking the derivative of the position function with respect to time. Alternatively, you can also use the area under a velocity-time graph to find the change in velocity over a given time interval.

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