A roll of ribbon is used to tie 12 gifts which will be given to teachers on Teacher's Day. Every gift requires a length of 1.85m. After tying all the gifts, it was found that 2/3 if the ribbon had been used. The remaining ribbon was cut into 12 pieces of the same length. Calculate the length of each piece of ribbon that had been cut..

correct answer:

b.(19,-2)

7.9m and 4.3°

step-by-step explanation:

let east be +x and north be +y, x = distance * cos θ, y = distance * sin θ  

for 3.5 south, y = -3.5  

for 8.2, x = 8.2 * cos 30 and y = 8.2 * sin 30  

for 15 west, x = -15  

total x = 8.2 * cos 30 – 15 ≈ -7.9  

total y = -3.5 + 8.2 * sin 30 = 0.6  

magnitude = [(8.2 * cos 30 – 15)^2 + 0.6^2)]^0.5  

the magnitude is approximately 7.9 m  

tan θ = y/x = 0.6/-7.9  

the angle is approximately 4.3˚ north of west