Answer:
time=4s
Explanation:
we know that in a RL circuit with a resistance R, an inductance L and a battery of emf E, the current (i) will vary in following fashion
, where
max=
Given that, at i(2)=
⇒
⇒
⇒
Applying logarithm on both sides,
⇒
⇒
⇒
Now substitute 
⇒
⇒
⇒
Applying logarithm on both sides,
⇒
⇒
⇒
now subs. 
⇒
also 
⇒
⇒
Answer:120 min
Explanation:
Given
Amanda spent
of her time after school doing Home work
And
of her remaining time riding her bike
It is given that she rode her bike for 45 minutes in a week
Let t be the time after school
therefore Amanda spend
in home work and
time is left
From remaining
time she spends
time riding her bike
therefore 
thus 
therefore time spent on home work is 
In the modern model of the atoms over 99.9℅ of the atom is made up of empty space
The common method would be to use Balance, If you think about it, on other planets, the balance weights change by the same factor as the object you are measuring. Your mass measured with a balance would be the same on the moon as it is on Earth. Weight is a measuring of gravity's effect on something. Mass is another story, it's the amount of matter in an object. Move to another planet and its object's weight will change, however, its mass will remain the same.