Explanation

After 3 half-lives, the remaining fraction is:

(1/2)³ = 1/8

Explanation

 m₁ = 2 kg, u₁ = 5 m/s  

- m₂ = 3 kg, u₂ = 1 m/s  

- Both moving in same direction  

- Relative speed of approach = u₁ − u₂ = 4 m/s

Explanation

F = k * (q₁q₂) / r²

Changes:  

- q₁ and q₂ → doubled → (2q)² = 4 times  

- r → halved → (½r)² = ¼  

So:  

F’ = k * (4q²) / (¼r²) = 16F

Explanation

- At launch point, both vertical and horizontal components of velocity exist.  

- At the highest point, vertical component is zero.  

- So, total velocity is maximum at launch.

Explanation

- At the midpoint, the electric fields due to each charge are equal in magnitude but opposite in direction, so they partially cancel out, making the net field weakest there.

Explanation

- Critical velocity is the maximum velocity at which fluid flows in laminar form.  

- Turbulent flow begins when the fluid exceeds this critical velocity.

Explanation

KE = ½ mv² = ½ × 0.5 × 6² = 0.25 × 36 = 9 J

Explanation

Constructive interference (max loudness) occurs when path difference = nλ  

(λ, 2λ, etc.)

Explanation

Gravitational force acts downward, so moving upward means work is done against gravity → negative work.

Explanation

Temperature coefficient α is defined as (Δρ / ρΔT)  

Unit = (Ω·m) / (Ω·m·°C) = 1/°C