1h----------------> 70x3=210 bacteria
2h-----------------> 210*3=630 bactaeria
let be y the number of bacteria at the t=0h
it is y=70 3^0
for t= 1h
y=70*3^1=210
for t=2h
y=70*3^2=630
so we can write y=70*3^x, where x is the number of hour
Answer: find the answer in the explanation
Explanation:
When a magnet is placed at the centre of the paper, and the nails are sprinkled on the paper, what will happen to the nails is that, the nails will form a pattern on the paper according to the magnetic field of the bar magnetic pole.
Other phenomena you can observe are:
1.) The nails will align themselves and show some lines of forces which is equivalent to the magnetic field lines
2.) The direction of the line of forces
3.) The strength of the magnetic field pole.
Answer:
The fraction fraction of the final energy is stored in an initially uncharged capacitor after it has been charging for 3.0 time constants is

Explanation:
From the question we are told that
The time constant 
The potential across the capacitor can be mathematically represented as

Where
is the voltage of the capacitor when it is fully charged
So at


Generally energy stored in a capacitor is mathematically represented as

In this equation the energy stored is directly proportional to the the square of the potential across the capacitor
Now since capacitance is constant at
The energy stored can be evaluated at as


Hence the fraction of the energy stored in an initially uncharged capacitor is
