Question

Q.3 Centripetal force 'F' acting on a particle of mass ‘m' moving in a circle of radius T
with velocity ‘v' depends on m, v and r. find the expression for F.
(2.
The rum and difference are equal in magnitude Find the angle between the vectors​

Answer 1

Q.3. Centripetal force F = mv²/r

Q.2. Let the two vectors be A and B with magnitudes A and B respectively.

Then magnitude of their sum is given by:

∣A + B∣ = √(A² + B² + 2ABcosθ) →(i) (θ= angle between the vectors)

Magnitude of their difference is given by:

∣A - B∣ = √(A² + B² - 2ABcosθ) →(ii)

As ∣A + B∣ = ∣ A − B∣

⇒√(A²+B²+2ABcosθ)=√(A²+B²−2ABcosθ)

⇒4ABcosθ=0

⇒ cosθ=0

⇒θ = 90°