Y directed force as a function of time

[tj77]

Homework Statement

Assume the mass of the plane is 300,000kg h = 10 miles L = 25 miles and vxo = 100 mi/hr.
Determine the lift(or y-directed force not including the force of gravity) as a function of time.

Relevant Equations

https://imgur.com/a/43fivhe

The question before asked to find the net force as a function of time which I got:

F = 4.83×10¹⁰ (1.65×10⁻⁸ t − 7.41×10⁻⁶) N

I just have no idea how to do it with the y directed force since I only have a horizontal acceleration equation.
Thanks so much to anyone that helps, I appreciate it!

 

[phinds]

Seriously, you're going to post something sideways so we have to get a kink in our neck looking at it?

 

[tj77]

Seriously, you're going to post something sideways so we have to get a kink in our neck looking at it?

Sorry I fixed it

 

[gneill]

Your problem is not well defined. What are h and L? What do they mean in the context of the problem? What does the net force (on what?) act on and how?'

You need to clearly state the entirety of the problem for Homework Helpers to provide meaningful help. Most will simply ignore your post otherwise; they don't have time to spare to play 20 questions as to what the actual problem statement is.

 

[collinsmark]

Problem Statement: Assume the mass of the plane is 300,000kg h = 10 miles L = 25 miles and vxo = 100 mi/hr.
Determine the lift(or y-directed force not including the force of gravity) as a function of time.
Relevant Equations:

The question before asked to find the net force as a function of time which I got:

F = 4.83×10¹⁰ (1.65×10⁻⁸ t − 7.41×10⁻⁶) N

I think your final force is off by a factor of around 10. Did you accidentally add another zero or multiply it by something you shouldn't have?

I just have no idea how to do it with the y directed force since I only have a horizontal acceleration equation.
Thanks so much to anyone that helps, I appreciate it!

What makes you think y is in the horizontal direction? Look at the equations: y is proportional to h, and h typically denotes height.

 

[tj77]

I think your final force is off by a factor of around 10. Did you accidentally add another zero or multiply it by something you shouldn't have?
What makes you think y is in the horizontal direction? Look at the equations: y is proportional to h, and h typically denotes height.

I think that's what my teacher said, but I could've heard him wrong

 

[collinsmark]

I think that's what my teacher said, but I could've heard him wrong

Ok, but you might want to re-think your horizontal vs. vertical. Anyway, double check your calculations or show your steps because I still think your final answer is off by about a factor of 10.

 

[tj77]

I did another post that might clear it up, thanks for your help I really appreciate it

 

[collinsmark]

I did another post that might clear it up, thanks for your help I really appreciate it

Your last post didn't seem to clear things up. Let me help you out,

If $h = 10 \ \mathrm{miles} = 16,093 \ \mathrm{m}$ and $m = 300,000 \ \mathrm{kg}$
then

$mh \neq 4.83 \times 10^{10} \ \mathrm{m \ kg}$

 

[tj77]

Your last post didn't seem to clear things up. Let me help you out,

If $h = 10 \ \mathrm{miles} = 16,093 \ \mathrm{m}$ and $m = 300,000 \ \mathrm{kg}$
then

$mh \neq 4.83 \times 10^{10} \ \mathrm{m \ kg}$

What equation would I use then?

 

[collinsmark]

What equation would I use then?

What is $16093 \times 300000$?

 

[tj77]

What is $16093 \times 300000$?

Oh I see its 4.8 X 10^9. So that would be the answer?

 

[collinsmark]

Oh I see its 4.8 X 10^9. So that would be the answer?

I should be asking you that.

But seriously, you should now be able to fix up your force equation in you initial post, and simplify it one final step.

All joking aside though, it would be beneficial for you to go through the problem and try to understand the meaning of each of the equations involved.

If you you would like more help, you can always show your steps complete with commentary on each step along with your impression of each of the original equations (i.e., what they mean, what they represent), and someone here will be happy to attempt help if there are any misconceptions.

 

[tj77]

I should be asking you that.

But seriously, you should now be able to fix up your force equation in you initial post, and simplify it one final step.

All joking aside though, it would be beneficial for you to go through the problem and try to understand the meaning of each of the equations involved.

If you you would like more help, you can always show your steps complete with commentary on each step along with your impression of each of the original equations (i.e., what they mean, what they represent), and someone here will be happy to attempt help if there are any misconceptions.

Ok thanks, will do

 

[tj77]

Ok thanks, will do

I should be asking you that.

But seriously, you should now be able to fix up your force equation in you initial post, and simplify it one final step.

All joking aside though, it would be beneficial for you to go through the problem and try to understand the meaning of each of the equations involved.

If you you would like more help, you can always show your steps complete with commentary on each step along with your impression of each of the original equations (i.e., what they mean, what they represent), and someone here will be happy to attempt help if there are any misconceptions.

I did it, if you would like to look

 

[Mark44]

@tj77, please don't add "Homework HELP!" or similar to your threads. Everyone who is posting here in the Homework Fora is by default asking for help for homework problems, so titling your posts like the above, or adding it to your thread title doesn't provide us with any information.

BTW, yours is an unusual problem, with the weight of the aircraft given in kg, but the distances and speeds in miles and miles/hour. Also, that's a very slow speed for the plane. It would probably fall out of the sky at that speed. The landing speed for a Boeing 737 is somewhere between 150 to 200 mi/hr.