The parallelogram method is restricted to the addition of just two
vectors. However, it is arguably the most intuitive way of adding twoforces acting on a point.
Algebraic addition and subtraction of vectors
Vectors in a straight line
Whenever you are faced with adding vectors acting in a straight line (i.e. some directed left and some right, or some acting up and others down) you can use a very simple algebraic technique:
Method: Addition/Subtraction of Vectors in a Straight Line
Choose a positive direction. As an example, for
situations involving displacements in the directions west and east, youmight choose west as your positive direction. In that case,
displacements east are negative.
Next simply add (or subtract) themagnitude of the vectors using the appropriate signs.
As a final step the direction of the resultant should be included in
words (positive answers are in the positive direction, while negativeresultants are in the negative direction).
Let us consider a few examples.
A tennis ball is rolled towards a wall which is 10 m away from the ball. If after striking the wall the ball rolls a further 2,5 m along the ground away from the wall, calculate algebraically the ball's resultant displacement.
We know that the resultant displacement of the ball
(
${\overrightarrow{x}}_{R}$ ) is equal to the sum of the ball's separate
displacements (
${\overrightarrow{x}}_{1}$ and
${\overrightarrow{x}}_{2}$ ):
Since the motion of the ball is in a straight line (i.e. the ball
moves towards and away from the wall), we can use the method of algebraic additionjust explained.
Let's choose the
positive direction to be towards the wall. This means that the
negative direction is away from the wall.
Suppose that a tennis ball is thrown horizontally towards a wall at an initial velocity of 3 m
$\xb7$ s
${}^{-1}$ to the right. After striking the wall, the ball returns to the thrower at 2 m
$\xb7$ s
${}^{-1}$ . Determine the change in velocity of the ball.
A quick sketch will help us understand the problem.
Remember that velocity is a vector. The change in the velocity of the
ball is equal to the difference between the ball's initial and finalvelocities:
Remember that in this case
towards the wall means a positive velocity , so
away from the wall means a negative velocity :
$\Delta \overrightarrow{v}=5m\xb7{s}^{-1}$ away from the wall.
vector is anything that has both a direction and a magnitude .they are usually drawn as pointed arrows ,the length of which represents a vector's magnitude
Tetteh
what is electronics?
Edward
how to calculate the reading on voltmeter or ammeter
Use previous years question papers to understand how questions are answered and asked
Joseph
but it hard ii am a slow learner
Slindile
Then the best thing to do is that immediately you are done reading through a certain topic, and you think you understood everything in that topic that's when you can use previous question papers and answer questions related to the topic. I think that's not difficult
Joseph
mm ii will try
Slindile
Good
Joseph
Here's a tip in reading textbooks, don't read it like a novel. First, flip through the pages—scan the chapter that you wanted to read. Second, go to the end of the chapter. Usually, there's a quiz at the end, so if will give you the important information that you need to know.
Sarah
Third, go to the beginning of the chapter and read through the words that were printed in bold: Titles, subtitles, headings, important words —because it helps to break down information.
Sarah
Fourth, read the first sentence of the chapter—if it is written by a good author; therefore, it will also have a good introduction. Check also the last sentence of the chapter to sum it up. Finally, read the whole chapter. You won't read it twice anymore.
Sarah
It looks hard, cause there are so much to do but read it thoroughly, it's easy and it will help you to save time and comprehend better. If you don't really have interest on reading—there are various of videos in youtube😊
Sarah
Oh, so em dashes turn into question marks :' (( nvm. Goodluck to all of us!
Sarah
How many ways can we calculate the empirical formula
the moment of a force" is a measure of a tendency to cause a
body to rotate about a specific point or axis....a moment is due to force not having equal and opposite force directly along
its line of action.
Bhuboy
how to calculate the magnitude of the force of repulsion