First of all, that's not an equation. An equation needs an 'equals' sign ( = ),
so you need something like
Amount present = a e^-0.0025t .
'a' = amount present when t = 0 .
The half-life is the time it takes for the original amount to decay to half of it.
That's just 't' when e^-0.0025t = 1/2
Take the natural log of each side: -0.0025t = ln(0.5)
Divide each side by -0.0025 : t = ln(0.5) / (-0.0025) =
(-0.69315) / (-0.0025) =
<em>t = 277.26 minutes</em>
( 4hrs 37min 15.5sec)
Rounded to nearest tenth: t = 277.3 minutes .
I think you would be using a topographic Map, So the answer should be A
They don't have free electrons moving around (delocalised electrons) so they can't conduct electricity which gives them the property of good insulators.
<span>This problem is relatively simple, in order to solve this problem the only formula you need to know is the formula for friction, which is:
Ff = UsN
where Us is the coefficient of static friction and N is the normal force.
In order to get the crate moving you must first apply enough force to overcome the static friction:
Fapplied = Ff
Since Fapplied = 43 Newtons:
Fapplied = Ff = 43 = UsN
and it was given that Us = 0.11, so all you have to do is isolate N by dividing both sides by 0.11
43/0.11 = N = 390.9 which is approximately 391 or C. 3.9x10^2</span>
