Question

The resultant of 2 forces 2p and root 2p is root 10p.what is the angle between the forces?.

Answer 1

F1 = 2p

F2 = √2p

R = √10p

We know,

R² = A² + B² + 2ABCosθ

==> 10p² = 4p² + 2p² + 2×2p×√2p× cos θ

===> 10p² - 6p² = 4√2p² cos θ

===> cos θ = 4p² / 4√2p²

===> cos θ = 1/√2

But,

cos 45° = 1/√2

So,

===> cos θ = cos 45°

===> θ = 45°

Hence, angle between the two forces is 45°