I have considered it by use of the sine and cosine functions. For example, you will notice that the x component for the 5N force will come up as negative.
There is an equation for area of a circle using radius: pi * radius * radius And an equation for area of a circle using diameter: pi * diameter * diameter / 4 It is more common that the diameter of objects are given rather than the radius so the second formula is more useful. A google search will also provide you with the same formula as I have used. "Area of a circle using diameter"
Thanks sir for the refreshment because it’s been like six years now I studied this. If I am not confused I believe the angle for the resultant force should be 360°-18.5° since all the angles of the other forces were taken from the posive x-axis for the calculation
I am doing engineering level 3 and I joined in late when they already finished this topic. I am grateful that I finally have learnt from you. Thanks for the video again. Keep on posting more great stuff.
We could have ignored the first part. There are two approaches to breaking down the forces into components shown in this video. The first approach treats the vectors as triangles, where we find the size of the components, then add up the x components (if right, it would be added; and to the left, it would be negative). The second approach treats the vector as a phasor (try google this term and you should see a video of a vector that rotates, and that this rotating vector can be used to draw a sine wave (for y component) and cosine wave (for x component)
Why didn't you keep -3.42 as a negative number and instead used it as a positive number, when calculating the angle and R using trigonometry and Pythagoras. Even though, all the sin values added up to the negative 3.42.
When I was doing the calculation at that stage, I was treating the system of forces as a right triangle. So I was finding the angle as per the diagram drawn at 8:00 into the video. I was calculation the magnitude of the angle and resultants shown and letting the diagram indicate the direction.
It would be more clear if I put it as the angle anti-clockwise as that is normal. At that time of making the video, I had made that decision because I had calculated the angle and was wanting to make it clear that angle was as measured clockwise from the axis. Both answers are right (measuring clockwise or anticlockwise); but different people have different conventions that they follow. In your case, you have been taught the convention that anti-clockwise measurement of angles is required. Using this anticlockwise is positive convention is good as it will set you up to use matrices in the future (should you learn this).
Thanks for the video, i learn a lot from it. I have a question, what will be the direction of a force whose vertical component is 0N and horizontal is 30N
Hi there, make sure you put in a second set of brackets. The number you have looks like the answer to 3.42*3.42+10.24 = 21.9364 It should be √((10.24)²+ (3.42)²) or the answer to √ (3.42*3.42+10.24*10.24)
