Question

The rate of formation of a radiocactive nuclei is 100 nuclei per second (lambda=0.5/sec). After how much time, total active nuclei will become 50? If there were 25 nuclei initially present?

Answer 1

Explanation:

As the body at rest explodes into two equal parts, they acquire equal velocities in opposite directions according to conservation of momentum. When the angle between the radius vectors connecting the point of explosion to the fragments is90∘, each radius vector makes an angle 45∘ with the vertical. To satisfy this condition, the distance of free fall AD should be equal to the horizontal range in same interval of time. AD=DB AD=0+12×10t2=5t2 DB=ut=10t \ 5t2=10t⇒t=2sec