Question

Q53. If the two forces are equal i.e when F1 =F2=F
(A) R= 2Fcos(8/2)
(B) R= Ftana
(C) R= 2Ftane/2
(D) R= 2tan/2​

Answer 1

Answer:

let a be the angle between f

1

and f

2

f

1

+f

2

=r

1

______(1)

f

1

+2f

2

=r

2

_____(2)

r

1

×r

1

=f

1

×f

1

+f

1

×f

2

=f

2

×f

1

×f

2

+f

2

r

12

=f

1

2

+f

2

2

+2×f

1

×F

2

a______(3)

f

1

×(f

1

+2f

2

)=f

1

×r

2

since f

1

andf

2

are perpendicular

f

1

r

2

=0.f

1

2

+2f

1

a=0by,equation (3) and (4)

$$ r_1^2 = f_1^2 = 2f_1 \times f_2 a + f_2^2 = 0 + f_2^2

r

1

=f

2