Question

consider two vectors A and B Where A-B and |A+B|=|A-2B| vector B is directed in the positive x_direction and A makes an angle of 60°above the positive x_axis find magnitude of the two vectors​

Answer 1

Answer:

It should be mentioned that an efficient way to work this vector addition problem is with the cosine law for general triangles (and since  

a

,

b

 and  

r

 from an isosecles triangle, the angles are easy to figure). However, in the interest of reinforcing the usual systematic approach to vector addition, we note that the angle  

b

 makes with the +x axis  is 30

0

+105

0

=135

0

(a) The x component of  

r

x

​

​

=(10.0m)cos30

0

+(10.0m)cos135

0

=1.59m

(b)  the y component of  

r

 is r

y

​

=(10.0m)sin135

0

 = 12.1 m.

(c) the magnitude of  

r

 is r =  ∣

r

∣=

(1.59m)

2

+(12.1m)

2

​

=12.2m

(d) The angle between  

r

 and the +x direction is tan

−1

[(12.1m)/(1.59m)]=82.5

0

Explanation: