[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y ] [Search | Home]
4Archive logo
Hey, /wsr/
If images are not shown try to refresh the page. If you like this website, please disable any AdBlock software!

You are currently reading a thread in /wsr/ - Worksafe Requests

Thread replies: 23
Thread images: 5
File: 1442953242938.jpg (15 KB, 250x250) Image search: [iqdb] [SauceNao] [Google]
1442953242938.jpg
15 KB, 250x250
Hey, /wsr/
Retard here. Can some of you help me with my Physics homework? I have a teacher I can't learn from.

#1: What horizontal force is necessary to accelerate a 215 kg trunk at 1.85 m/s^2 along a flat surface with a coefficient of kinetic friction of 0.32?

#2: A helicopter with a mass of 1450 kg is moving with an acceleration of 1.27 m/s^2 upwards. What is the magnitude of the lift force provided by the propeller?
>>
File: 1441755095072.jpg (792 KB, 2048x1356) Image search: [iqdb] [SauceNao] [Google]
1441755095072.jpg
792 KB, 2048x1356
>>43711
Bumping with qt
>>
File: 1420393260003.jpg (88 KB, 500x552) Image search: [iqdb] [SauceNao] [Google]
1420393260003.jpg
88 KB, 500x552
>>43711
Plz halp.
>>
File: 1443632768918.jpg (26 KB, 241x274) Image search: [iqdb] [SauceNao] [Google]
1443632768918.jpg
26 KB, 241x274
>>43711
>>
>>43711
Plz /wsr/,
You're my last hope.
>>
>>43711
Plzzzzzzzzzzzzzzzzzzzzzzzz
>>
>>43711
You want the answer or an explanation?
>>
>>43724
Both please.
>>
>>43711
1. Ftotal=ma+Ffriction
Ffriction=0.32*2150(the normal force of the trunk)
Therefore F=215*1.85+0.32*2150=1085.75N

2. F=m(a+g) because it has to counteract gravity and provide vertical acceleration, so it's 215*(1.27+10(or 9.8 who cares))=16341.5N
>>
>>43725
Do you even know how to draw the free-body diagrams?
>>
>>43733
Thank you so much. I love you, anon.
>>
>>43734
Yeah, but past that point I don't get any of this shit. Almost everybody in my class is struggling. I think it might be the teacher.
>>
>>43711
>A helicopter with a mass of 1450 kg is moving with an acceleration of 1.27 m/s^2 upwards. What is the magnitude of the lift force provided by the propeller?
So as we learned, force=mass*acceleration.

Literally all we do is plug the values in, and out comes the answer:

f=m*a
=1.27*1450
=1841.5N <-- remember the units!

EXCEPT!

The question doesn't actually state this (bad Physics question!), but we should probably assume that this helicopter is on Earth.

If it is, the lift force has to hold the helicopter up as well as accelerate it upwards, so we need to calculate the weight of the helicopter and add it to the acceleration force to get the total lift force.

weight = mass * coefficient of gravity
W = m * g

On Earth, g = 9.81, so

W = 1450 * 9.81 = 14224.5N

Total lift = 1841.5 + 14224.5 = 16066N
>>
>>43711
F_x=F-f=ma_x
F_y=N-mg=0 (it doesn't move in the y-direction)
F=ma_x+f but f=u_k*N and N=mg so
F=m_ax+u_k*N

F_y=F-mg=ma_y
F=ma_y+mg
>>
File: 1424126784437.gif (2 MB, 200x150) Image search: [iqdb] [SauceNao] [Google]
1424126784437.gif
2 MB, 200x150
>>43743
WHAT THE FUCK IS THAT?!
>>
>>43733
Wait, how is the mass 215 for #2?
>>
>>43745
The equations from the free-body diagrams. The underscores show the axis it is related to so F_x is the sum of the forces in the x-direction and a_x is the acceleration in the x-direction. Also are you under 18? This stuff is sophomore level at best.
>>
>>43752
He made a mistake. Just replace it with the actual mass.
>>
>>43754
No, I'm just retarded and have a teacher that goes too fast for me.
>>
>>43763
Did you actually learn anything from this thread?
>>
>>43754
Maybe that's how you write it in whatever crazy place you come from, but there's no way you wrote that as anything other than a dick-swinging exercise.

You've got someone saying "please explain this physics problem to me, my teacher isn't making sense", and you spout a load of shite that looks like Perl at him.

That's not helping, that's just showing off.

Also you got fristed, so you couldn't even belittle a college kid without fucking it up.
>>
>>43768
Not yet. I'm hoping I can learn from the explanations.
>>
>>43770
Sorry if I somehow offended you.
Thread replies: 23
Thread images: 5
Thread DB ID: 472964



[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y] [Search | Home]

[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / qst / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y] [Search | Home]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.
This is a 4chan archive - all of the shown content originated from that site. This means that 4Archive shows their content, archived. If you need information for a Poster - contact them.
If a post contains personal/copyrighted/illegal content, then use the post's [Report] link! If a post is not removed within 24h contact me at wtabusse@gmail.com with the post's information.