A becomes positive, while b is now negative. Basically, electrons are negative particles. If they go to somewhere, they make the somewhere they go to negative.
Answer:
The combined speed of the woman and the skateboard is 6.67 m/s.
Explanation:
It is given that,
Mass of woman, m₁ = 60 kg
Speed of woman, v = 10 m/s
The woman jumps onto a giant skateboard of mass, m₂ = 30 kg
Let V is the combined speed of the woman and the skateboard. It can be calculated using the conservation of momentum as :

On solving the above equation we get V = 6.67 m/s
So, the combined speed of the woman and the skateboard is 6.67 m/s. Hence, this is the required solution.
Answer:
0.9972 fraction of plutonium will remain after 100 years.
Explanation:
Half life of plutonium = 
Let the initial mass of plutonium be = 
Mass of plutonium after time of 100 years = A
Decay constant for this process = 




0.9972 × 100 = 99.72 %
0.9972 fraction of plutonium will remain after 100 years.