Question

So...i need help pleaseeeeeee

Answer 1

which question? both? I love web assign, haha

Answer 2

Q7: you need to find the v_y component. You can do this two ways. Either as the side of the triangle undefined, via pythagora theorem (quickest way), or by using cos(theta) = O/H = 0.34/0.59 ---> theta = 54.8 degrees. Then the swimmers component straight across is 0.59sin(54.8).

We do this because the 13m displacement is in that exact direction. You now have a straight distance, the effective speed over that distance, and you can calculate a time :)

Answer 3

Q8: you need to find the resultant force of the two force vectors.

x direction: Top person is 15cos(30), bottom person is 10cos(50).**
y direction: Top is 15sin(30), bottom is 10sin(50)

add the total x and total y (careful with y, they are in opposite directions).

Now you can use pythagora's theorem to work out the addition of these two answers. (you have the two short sides of a triangle). the angle will be found using inverse tangent (Opp/Adj).

**[do you know that the components of a vector can be found a quick way, if it is swung *through* the angle, it will always be the vector*cosine(angle). Swung away is it always vector*sin(angle). As long as this takes place inside a 90 degree section (as in between x and y axis)]

Answer 4

Last part of 8:

you know m =12kg, F = answer to part a), so you can find the acceleration. It starts at 0m/s, ends at 12m/s, you can solve for a time.

Answer 5

You sir, are a life saver! thank you so much.!