Help me study for my physics test tomorrow! - Music Banter Music Banter

Go Back   Music Banter > Community Center > The Lounge
Register Blogging Today's Posts
Welcome to Music Banter Forum! Make sure to register - it's free and very quick! You have to register before you can post and participate in our discussions with over 70,000 other registered members. After you create your free account, you will be able to customize many options, you will have the full access to over 1,100,000 posts.

Reply
 
Thread Tools Display Modes
Old 02-07-2012, 08:02 PM   #11 (permalink)
Music Addict
 
Join Date: Mar 2009
Posts: 1,711
Default

Ok a little heads up I noticed with the dumb google calculator

tan(20 degrees) is actually equal to 0.36, not sure why google calculator was giving me that other number. But the steps are the same. So the first answer is actually something like 27.

And yes you're answer looks right
midnight rain is offline   Reply With Quote
Old 02-07-2012, 08:05 PM   #12 (permalink)
Partying on the inside
 
Freebase Dali's Avatar
 
Join Date: Mar 2009
Posts: 5,584
Default

Oh, one more thing about trig real quick. If I want to find the angle of a right triangle, I know I need to use inverse sin, cos, or tan.

Walk me through the steps of finding the angle of a right triangle whose hypoteneus is 5 units, and whose opposite side is 7 units.
__________________
Freebase Dali is offline   Reply With Quote
Old 02-07-2012, 08:09 PM   #13 (permalink)
Music Addict
 
skaltezon's Avatar
 
Join Date: Nov 2010
Location: hairball cluster
Posts: 326
Default

opposite side can't be larger than the hypotenuse
. . .but if the numbers are reversed, you have

sin(x) = 5/7 = .7

x = arcsin (.7)
skaltezon is offline   Reply With Quote
Old 02-07-2012, 08:09 PM   #14 (permalink)
Music Addict
 
Join Date: Mar 2009
Posts: 1,711
Default

Quote:
Originally Posted by Freebase Dali View Post
Oh, one more thing about trig real quick. If I want to find the angle of a right triangle, I know I need to use inverse sin, cos, or tan.

Walk me through the steps of finding the angle of a right triangle whose hypoteneus is 5 units, and whose opposite side is 7 units.
I think it's as simple as arcsin(7/5). Just put that into your calculator.

It's basically just the reverse, there's no steps involved, unless it was values used on 45-45-90 triangles or 30-60-90

Plus what skaltezon said LOL
midnight rain is offline   Reply With Quote
Old 02-07-2012, 08:12 PM   #15 (permalink)
Partying on the inside
 
Freebase Dali's Avatar
 
Join Date: Mar 2009
Posts: 5,584
Default

K. Disregarding the fact that my triangle is breaking all the rules, I would simply divide the opposite side by the hypoteneus and multiply that number by the inverse of sin? That works for me.
__________________
Freebase Dali is offline   Reply With Quote
Old 02-07-2012, 08:12 PM   #16 (permalink)
The Music Guru.
 
Burning Down's Avatar
 
Join Date: Jun 2009
Location: Beyond the Wall
Posts: 4,858
Default

Quote:
Originally Posted by Freebase Dali View Post
Oh, one more thing about trig real quick. If I want to find the angle of a right triangle, I know I need to use inverse sin, cos, or tan.

Walk me through the steps of finding the angle of a right triangle whose hypoteneus is 5 units, and whose opposite side is 7 units.
Hypotenuse is always smaller than the opposite. If I recall correctly, you can plug in arcsin(7/5) in a calculator to get your answer.

edit: damn, I was too slow
Burning Down is offline   Reply With Quote
Old 02-07-2012, 08:13 PM   #17 (permalink)
Music Addict
 
Join Date: Mar 2009
Posts: 1,711
Default

Quote:
Originally Posted by Freebase Dali View Post
Word. Ok. So I have the basics. Now, when doing 2 dimensional kinematics, that trig comes into play, but I also have to remember some formulas. I can put those on my phone, so I'm not worried too much about it, since my phone is also my calculator, which is allowed.

So, how would you guys go about solving something like this (taken from a homework problem):

A projectile is launched from and returns to ground level. Air resistance is absent. The horizontal range of the projectile is R = 175 m, and the horizontal component of the launch velocity is Vox = 25 m/s. Find the vertical component Voy of the launch velocity.
I haven't taken college physics but isn't the equation just displacement = velocity * time ?
midnight rain is offline   Reply With Quote
Old 02-07-2012, 08:15 PM   #18 (permalink)
The Music Guru.
 
Burning Down's Avatar
 
Join Date: Jun 2009
Location: Beyond the Wall
Posts: 4,858
Default

Quote:
Originally Posted by Freebase Dali View Post
K. Disregarding the fact that my triangle is breaking all the rules, I would simply divide the opposite side by the hypoteneus and multiply that number by the inverse of sin? That works for me.
Yes. That will give you the angle.
Burning Down is offline   Reply With Quote
Old 02-07-2012, 08:16 PM   #19 (permalink)
Partying on the inside
 
Freebase Dali's Avatar
 
Join Date: Mar 2009
Posts: 5,584
Default

Quote:
Originally Posted by Tuna View Post
I haven't taken college physics but isn't the equation just displacement = velocity * time ?
Well displacement is actually velocity over time (d = v/t) if I remember correctly, but that's one dimensional. The problem has both the x and y dimension, and is asking for the components of the vector, which the vector would be a diagonal line. I would need to figure out the x component and the y component that made the resultant vector.
__________________
Freebase Dali is offline   Reply With Quote
Old 02-07-2012, 08:17 PM   #20 (permalink)
Music Addict
 
skaltezon's Avatar
 
Join Date: Nov 2010
Location: hairball cluster
Posts: 326
Default

Quote:
Originally Posted by Freebase Dali View Post
K. Disregarding the fact that my triangle is breaking all the rules, I would simply divide the opposite side by the hypoteneus and multiply that number by the inverse of sin? That works for me.
No. Find the value of 5/7 and look in a table to see what angle has that sine value. Or use your scientific calculator, if that's permitted.
skaltezon is offline   Reply With Quote
Reply


Similar Threads



© 2003-2024 Advameg, Inc.