Question

help @vocaloid

Answer 1

1 is a

Answer 2

2 is b

Answer 3

3 is d

Answer 4

4 is c

Answer 5

check # 2 again, you made a sign error

Answer 6

2 is d

Answer 7

good, and the other ones 1,3, 4 are correct

Answer 8

so you'll need to find: the dot product, the magnitudes of u and v, and plug them into equation 3 to find theta

Answer 9

2 is a

Answer 10

@Vocaloid

Answer 11

good

Answer 12

for 3) calculate the vector for the displacement by subtracting final distance vector - intial vector, then find the dot product of force and displacement

Answer 13

1 c?

Answer 14

@Vocaloid

Answer 15

hold on I just need to re-do the calculations b/c I'm getting a weird # :S

Answer 16

c for 3 maybe need to do problem

Answer 17

redo

Answer 18

alright, for #1: let's start from the top, what did you get for the dot product

Answer 19

-12
-16

Answer 20

good, so when you add those together you get -12 - 16 = -28

what about the magnitudes of u and v?

Answer 21

so I'm squaring again right?

Answer 22

magnitude = r = sqrt(x^2+y^2)

calculate the magnitudes of u and v

Answer 23

is the answer a

Answer 24

please follow my instructions

Answer 25

ok so 20

Answer 26

check your calculations again

the vector u has x-coordinate -2 and y-coordinate 8

plug these into the magnitude formula to find the magnitude of u.

Answer 27

7.7

Answer 28

good but we can leave it in radical form until the end, so sqrt(68)

repeat the same thing with the coordinates of v

Answer 29

5.7

Answer 30

or leave it in radical form

Answer 31

yeah we can just leave it in radical form so we don't lose accuracy until the every end

so

cos(theta) = -28/sqrt(68*40), solve for theta

Answer 32

It's d then

Answer 33

@Vocaloid

Answer 34

good

Answer 35

3 c/

Answer 36

good, 3 = C