Answer: 2.67 m/s
Explanation:
Given
Mass of block A is 
mass of block B is 
The initial velocity of block A 
the initial velocity of block B is 
After collision velocity of block A is 
Conserving momentum
The momentum of block A after the collision is 
Therefore, there is no change in sign.
Answer:
Explanation:
Energy of system of charges
= k q₁q₂ / r₁₂ + k q₁q₃ / r₁₃ + k q₃q₂ / r₃₂
q₁ , q₂ and q₃ are charges and r₁₂ , r₁₃ , r₃₂ are densities between them
9 x 10⁹ ( 2x2 x10⁻¹²/ .25 + 2x2 x10⁻¹²/ .25 + 2x2 x10⁻¹²/ .25 )
= 9 x 10⁹ x 3 x 16 x 10⁻¹²
= 432 x 10⁻³
= .432 J .
Most likely it would be C not completely sure
You don't need to worry about the 10 year bit with this question. Just grab a calculator and divide 100/2, then the answer to that (50) by 2 etc and keep dividing by 2 until you get down to 6.25.
The answer ends up being 4 half lives :)
If you don't understand what a half life is please let me know :)
