Question

Suppose a different windmill has its center at (0, 0). Its blades make a complete rotation in 20 seconds. If the tip of one blade is located at (4, 3), after 5 seconds where is the tip of the blade located?

https://courseplayer.avalearning.com/NeutralLMS/coursefiles/Questions/847850/windmill.png

Answer 1

can you draw a picture of the problem ?

Answer 2

open that website it will show the picture

Answer 3

yes, but this is a different windmill, with its center at 0,0
to solve the problem you should sketch what is going on

Answer 4

ohh okay

Answer 5

will i got (-3,4)

Answer 6

how?

Answer 7

its at (4, 3) it will move to (4, -3) assuming its rotating clockwise...
not (-3,4)

Answer 8

that is the first problem, which way is it rotating? in the picture for the other problem, it shows counter-clockwise.

But 5 seconds is ¼ of 20 seconds, meaning it rotates 90º
if you start at (x,y), 90º means you are at either (y, -x) or (-y, x)
depending on which way you are turning.

Answer 9

it didnt tell me which way it is turning
and i assume its going clockwise

Answer 10

Then after rotating through 90° more, the blade will be at
(5 cos(α + 90°), 5 sin(α + 90°)) = (-3, 4)
is it?

Answer 11

if you start at (4,3), and rotate 90º clockwise, the x coord will remain positive
we will be at (3,-4)

if you start at (4,3) and rotate c c w 90º, we will be at (-3, 4)
I am not (explicitly) using trig for this, just the rule, sway the x and y coordinates, and negate one of them

Answer 12

the answers are

(3, 4)
(0, 3)
(-3, 4)
(-4, -3)

Answer 13

in that case, it's easy. It looks like they did a counter-clockwise rotation.

Answer 14

its goin to be (-3,4)

Answer 15

the other option, rotating clockwise would put us at (3, -4), and that choice is not on your list.

Answer 16

yea

Answer 17

its the rite answer (-3,4)
i got it correct

Answer 18

thank you every much
this was confusing.