Answer:
t=1.4hours
Explanation:
The half life is 1hour
At t=0 he has a mass of 4kg
So he want it to be 1kg, so that his weapon can work.
Applying the exponential function of decay
M=Cexp(-kt)
Where,
M is the mass at any time
C is a constant of integration
k is the rate of decay
Given that it has an half life of 1 hours.
Then k is 1
At t =0 the mass is 4kg
Therefore
4=Cexp(0)
C=4
M=4exp(-kt)
Since rate of decay is 1, then k=1
M=4exp(-t)
We need to find t at M=1kg
1=4exp(-t)
1=4exp(-t)
1/4=exp(-t)
0.25=exp(-t)
Take In of both sides
In(0.25)=-t
-1.3863=-t
Then, t=1.386hour
Then it will take about 1.4 hours to get to 1kg.
I'm pretty sure that the "block" of which you speak is one in a pattern
of them that covers the drawing you have of the rectangle, and now
I need to explain something to you:
The REASON for printing that drawing next to the question that you
partially copied is that the drawing has information that's needed to
answer the question with, and rather than repeat all that information
in the question, it just says "LOOK AT THE DRAWING !"
In fact, the whole point of the question may not be just to remind you of
what "perimeter" means. It's more likely that the purpose of this problem
is to make you pick the information you need off of a drawing.
Either way, if you'll kind of "read between the lines" of the part of the
question that you DID copy, it should be pretty obvious to you that nobody's
going nowhere in the direction of a solution without SEEing the drawing.
So my bottom-line conclusion regarding a solution for this problem is:
Not possible with the given information.
Answer:
The horizontal distance travelled in that time lapse is 12.94 m
Explanation:
In order to solve this problem, we'll need:
- The horizontal speed
- the time the hammer takes to fall from the roof to the ground
At the lowest point of the roof, the hammer has a 9.88 m/s speed that makes an angle of 27° with the horizontal, so we can calculate the horizontal and vertical speed with trigonometry. If we take right as x positive and down as y positive we get
Now, we make two movement equation as we have a URM (no acceleration) in x and an ARM (gravity as acceleration) in y. We will wisely pick the lowest point of the roof as the origin of coordinates
Now we calculate the time the hammer takes to get to the floor
or 
Now, we keep the positive time result and calculate the horizontal distance travelled
