Vector-A-of-magnitude-20-unit-lies-in-the-direction-45-S-of-E-while-vector-B-of-magnitude-30-units-in-the-direction-60-W-of-N-calculate-the-scaler-product-A-B-

Question Number 9715 by tawakalitu last updated on 28/Dec/16

Vector \vec{A} of magnitude 20 unit, lies in the

direction 45 ° S of E while vector \vec{B} of magnitude

30 units in the direction 60 ° W of N .

calculate the scaler product \vec{A} \cdot \vec{B}

Answered by sandy_suhendra last updated on 28/Dec/16

Commented by sandy_suhendra last updated on 28/Dec/16

the angle between \vec{A} and \vec{B} = 165 °

\vec{A} . \vec{B} = ∣ \vec{A} ∣ . ∣ \vec{B} ∣ \cos 165 °

= 20 \times 30 \times (- 0.966)

= - 579.6 unit

Commented by tawakalitu last updated on 28/Dec/16

God bless you sir . i really appreciate .

Commented by geovane10math last updated on 29/Dec/16

O t h e r w a y \dots

60 ° + 45 ° + x = 270 °

x = 270 ° - 105 °

x = 165 °