Physics Help Forum

Physics Help Forum (http://physicshelpforum.com/physics-help-forum.php)
-   Kinematics and Dynamics (http://physicshelpforum.com/kinematics-dynamics/)
-   -   Hi guys (http://physicshelpforum.com/kinematics-dynamics/7788-hi-guys.html)

Duha Oct 21st 2013 09:15 AM

Hi guys
 
I have 2 questions and I need your help please ^__^

1: Using components determine the sum of + if = 3 m [N30W] and = 2 m [N10E].

2: A force of 3.0 N and 1.0 N act as shown. What is the acceleration of the 6.0 kg mass?

http://www2.0zz0.com/2013/10/21/16/491079930.gif

topsquark Oct 21st 2013 12:05 PM

Quote:

Originally Posted by Duha (Post 22186)
1: Using components determine the sum of + if = 3 m [N30W] and = 2 m [N10E].

Please let me be the first to say: "What??" This makes no sense. Can you write out the full problem?

Quote:

Originally Posted by Duha (Post 22186)
2: A force of 3.0 N and 1.0 N act as shown. What is the acceleration of the 6.0 kg mass?

http://www2.0zz0.com/2013/10/21/16/491079930.gif

For this one you'll want to find the net force acting on the block in components in the usual +x and +y directions. Do you know how to do this?

-Dan

Duha Oct 21st 2013 12:41 PM

Hi :)
I`m so sorry with the first question

1) 1: Using components determine the sum of a + b if a = 3 m [N30W] and b = 2 m [N10E].


And the second question, by using sine and cosine for horizontal and vertical
but i don`t know how to sort the solution. :(


Thanks a lot for you.

topsquark Oct 21st 2013 02:40 PM

Quote:

Originally Posted by Duha (Post 22191)
1) 1: Using components determine the sum of a + b if a = 3 m [N30W] and b = 2 m [N10E].

Let's start simple:
Call East the +x axis and North the +y axis. Then we know that a is 3 m long at an angle of 30 degrees above the -x axis. So if we draw the usual triangles to get the components we have that a_x = - (3 m)*cos(30) and a_y = (3 m)*sin(30).

What are the components of the b vector?

-Dan

Duha Oct 24th 2013 08:36 AM

I`m so sorry for being late :(

The components of vector b it will be (2 m)*cos(10) and (2 m)* sin(10) ?!

ChipB Oct 24th 2013 11:29 AM

Quote:

Originally Posted by Duha (Post 22267)
I`m so sorry for being late :(

The components of vector b it will be (2 m)*cos(10) and (2 m)* sin(10) ?!

Yes, correct.

Duha Oct 24th 2013 11:39 AM

And then a + b will be ????

ChipB Oct 24th 2013 12:57 PM

Add a_x and b_x to get the total x-component, then add a_y and b_y to get the total y-component. The magnitide of the resulting vector is from Pythagoras: sqrt(x^2 + y^2). Its direction is calculated using trig: arctan(angle) = x/y to get angle east or west from north.

Duha Oct 26th 2013 09:27 AM

So for a_x will be (3 m)*cos(30) + (2 m)*cos(10)
and
a_y (3 m)*sin(30) + (2 m)*sin(10)

is that right ????!!!!

Duha Oct 30th 2013 09:27 PM

I solved the first question guys :)
Could you please now help me with the second one ^__^


All times are GMT -7. The time now is 11:54 AM.

Copyright © 2016 Physics Help Forum. All rights reserved.
Copyright © 2008-2012 Physics Help Forum. All rights reserved.