Vector V1 is 7.48 units long and points along the -x axis. Vector V2 is 4.97 units long and points at +35.0°?

Question

V1x =
V1y =
V2x =
V2y =

(b) Determine the sum V1 + V2.
Magnitude

Direction
° (counterclockwise from the +x axis is positive)




? help please

Answer 1

Vx = V*cos theta

Vy= V*sin theta

V1x = 7.48 * cos 180= -7.48
its 180 because its point along the -x axis

V1y = 7.48*sin 180 = 0

V2x = 4.97 *cos 35 = 4.07

V2y = 4.97 *sin 35 = 2.85


Vx = -7.48 + 4.07 = -3.41

Vy = 0 + 2.85 = 2.85

magnitude is V =square root ( - 3.41^2 + 2.85^2 )= 4.44

to get direction

arc tan (Vy/Vx) = arc tan (2.85/-3.41) = -39.89 + 180 = 140.11

to the post above me u forgot to multiply 4.97 to the cos of 35

Answer 2

V1x = 7.48 * COS 180 = -7.48
V1y = 7.48 * SIN 180 = 0
V2x = 4.97 * COS 35 = 0.82
V2y = 4.97 *SIN 35 =2.85

V1x + V2x = -7.48+ 0.82 = -6.66
V1y + V2y = 0 + 2.85 = 2.85

(b) Determine the sum V1 + V2.
Magnitude
V1 + V2 = SQRT (Vx^2 + V2y^2 = (44.36 + 8.12) = 7.24

Direction
Theta = INV TAN (Vy/Vx = 2.85/-6.66) = -23.17 degrees
This is with the Y axis at zero. Subtract 90 degrees to place find the answer with the X Axis at zero.
-23.17 - 90.00 = -113.17 degrees

I would add 360 degrees to this and call it 336.83.