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# M1 Vectors help please watch

1. http://pmt.physicsandmathstutor.com/...hapter%206.pdf

I'm stuck on Exercise g, question 5, I don't understand why resolving in the x and y direction doesn't seem to work, but multiplying 5 by the sin of the angles does work?

Use control f and copy and paste in "Exercise g, question 5"
2. Depends on how you did it using the x y method
3. It's a right angled triangle so using the trigonometric method is easy
4. (Original post by Droneon)
It's a right angled triangle so using the trigonometric method is easy
I'm still confused, could you explain how you'd use the trig method here?
5. Start by drawing a vector diagram. W acts downward, Ta is downward 40 degrees to the horizontal, Tb is upwards 50 degrees to the horizontal. That gives you a right angled triangle if you follow the rules of drawing a vector diagram (head to tail). The angles inside the triangle can be determined by subtraction from 90. That gives you a triangle with angles 40,50 and 90.
Then use the sin rule opposite/hypotenuse, so sin 40=Ta/5 so Ta=5sin40. Same thing for Tb.
6. (Original post by Droneon)
Start by drawing a vector diagram. W acts downward, Ta is downward 40 degrees to the horizontal, Tb is upwards 50 degrees to the horizontal. That gives you a right angled triangle if you follow the rules of drawing a vector diagram (head to tail). The angles inside the triangle can be determined by subtraction from 90. That gives you a triangle with angles 40,50 and 90.
Then use the sin rule opposite/hypotenuse, so sin 40=Ta/5 so Ta=5sin40. Same thing for Tb.
I'm confused how the 5 is the hypotenuse and how Ta is opposite the 40 degrees angle. Isn't the side opposite the 40 degrees Tb and isn't the hypotenuse (AB) unknown? Have you made a different triangle to the APB triangle?
7. No the hypotenuse is weight of P which is 5N.
Tb acts to the right, upwards, and 50 degrees to the horizontal. And start Ta from where Tb ends, andTa acts to the left, upwards (my bad I said downwards before), and 40 degrees to the horizontal. And W which is 5 joins the head of Ta to the tail of Tb. So the angle between Ta and Tb is 90, between Tb and W is 40 (cuz 90-50), and between Ta and W is 50 (cuz 90-40). And so W is the hypotenuse side a and Ta and Tb are the sides b and c of the right angled triangle.

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