can you do this?

Classical Mechanics Level 2

Two forces H H and I I are 6 N 6N at 3 6 ∘ 36^\circ to the positive x-axis and 7 N 7N along the negative x-axis. Find the resultant force?

12.37 14.56 15.23 19.25

Samuel Ayinde by samuel ayinde , 24, Nigeria

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Samuel Ayinde
Jun 18, 2014

using cosine rule, R 2 = A 2 + B 2 − 2 A B cos ⁡ R R^{2} = A^{2} + B^{2}- 2AB\cos{R}

R 2 = 6 2 + 7 2 − 2 ( 6 ) ( 7 ) cos ⁡ 2 R^{2} = 6^{2} + 7^{2}- 2(6)(7)\cos{2}

R 2 = 36 + 49 ( − 84 × − 0.8090 R^{2} = 36 + 49 (-84 \times -0.8090

R 2 = 85 + 67.956 R^{2} = 85 + 67.956

R 2 = 152.956 R^{2} = 152.956

R = 152.956 R = \sqrt{152.956}

R = 12.368 N R = 12.368N

R = 12.37 N R = 12.37N

1 Helpful 0 Interesting 0 Brilliant 0 Confused

This is completely wrong. The vectors are pointing in opposite directions, so the answer is going to be more like 2 and the angle must be given also. This is the problem with teaching physics as a list of equations to be applied blindly.

Michael Horton - 6 years, 11 months ago

FYI, to type latex, you just need to use the brackets \ ( \ ) (no spaces) as opposed to typing \ { \ }. I've updated the question, so you can look at it for reference.

Calvin Lin Staff - 6 years, 11 months ago

Log in to reply

eh bro i don't get it.

samuel ayinde - 6 years, 11 months ago

Log in to reply

I see that you fixed the brackets in your solution, so that's great!

For your equations, to get the power to display correctly, you should use { } instead of [ ].

E.g. 1^{23} is displayed as 1 23 1^{23} whereas 1 [ 23 ] 1^[23] is displayed as 1 [ 23 ] 1^[23]

The same applies to \sqrt{123}. In general, { } is used to indicate a block of text, whereas [ ] are treated as normal square brackets.

I fixed the first equation, so you can use that as a reference. You're doing great for learning Latex. Keep it up!

Calvin Lin Staff - 6 years, 11 months ago

Log in to reply

@Calvin Lin – thanks i'm alraedy getting it. @Calvin Lin

samuel ayinde - 6 years, 11 months ago

ok bro i will do that now

samuel ayinde - 6 years, 11 months ago

In this given case, it is easy to get the answer because the resultened vector will not be more than the twice of given greater vector..!!

Shan PS - 6 years, 11 months ago

For any given two vectors, the resultant lies between the sum and the difference of the two vectors.

R.l. Bhat - 6 years, 11 months ago

brother i think correct ans is 9.175 N.

manish kumar singh - 5 years, 7 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...