Resultant Forces. Need Help!

I had read this Formula Somewhere,

That If Two Forces act at An angle theta, The resultant Force is

$\sqrt{{a}^{2}+{b}^{2}-2 Cos Theta}$

Is it Correct? Also, I want to Know, If a force acts At an Angle Theta From horizontal, What is the Resultant Force?

Kindly Provide me With the Formulas. I shall study Further From the Wiki. Thanks!

#Forces #Help #Motion #Thanks #Resultants

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Comments

It is $\sqrt{a^2 + b^2 + 2ab\cos(\theta)}$ , where $\theta$ is the angle between the two vectors.

Edited for clarity.

Siddhartha Srivastava - 6 years, 1 month ago

Between The root of the Two vectors means? Can you give an example?

Mehul Arora - 6 years, 1 month ago

:/ I don't know why I wrote that.Disregard that. Basically, the angle between the vectors has to be taken when both of them have the same starting point. For example, this is the correct angle,

Img

While the angles in the pic below this is wrong. Notice how the vectors don't have the same starting points in the example below.

Img

Siddhartha Srivastava - 6 years, 1 month ago

@Siddhartha Srivastava – Okay! If a force acts At an Angle Theta From horizontal, What is the Resultant Force?

Mehul Arora - 6 years, 1 month ago

@Mehul Arora – If there is exactly one force, then the resultant force would be equal to the force itself.

Siddhartha Srivastava - 6 years, 1 month ago

@Siddhartha Srivastava – I got it. Thanks For your help @Siddhartha Srivastava

Mehul Arora - 6 years, 1 month ago

Math	Appears as
Remember to wrap math in `\(` ... `\)` or `\[` ... `\]` to ensure proper formatting.
`2 \times 3`	$2 \times 3$
`2^{34}`	$2^{34}$
`a_{i-1}`	$a_{i-1}$
`\frac{2}{3}`	$\frac{2}{3}$
`\sqrt{2}`	$\sqrt{2}$
`\sum_{i=1}^3`	$\sum_{i=1}^3$
`\sin \theta`	$\sin \theta$
`\boxed{123}`	$\boxed{123}$