True. all squares have opposite sides which are equal in length. this is the same for rectangles.
Answer:
8
Step-by-step explanation:
m=30 n=1/4
0.1*30+8-12*1/4
3+8-12*1/4
=3+8-3
=8
Answer: D The upward tension force in the cable is equal to the downward force of gravity.
Step-by-step explanation:
Answer:
1) 1:10
2) 150:2
3) 1:3
4) 20hrs : 1hrs
Step-by-step explanation:
Answer:
Ok, an exponential decay is written as:
P(t) = A*(1 - r)^t
Where A is the initial population, r is the rate of decay and t is the unit of time.
We know that the initial population is 15g
then:
P(t) = 15g*(1 - r)^t
And at t = 3hs, the populations is 5g
P(5h) = 5g = 15g*(1 - r)^5
5/15 = 1/3 = (1 - r)^5
(1/3)^(1/5) = (1 - r) = 0.8
Now, the half life time of the sustance is t = x, such that the population reduces to it's half:
P(x) = A/2 = 15g/2 = 7.5g
Then:
7.5g = 15g*0.8^x
7.5g/15g = 1/2 = 0.8^x
Now, remember that if we have:
a = b^x
then
x = ln(a)/ln(b)
ln(1/2)/ln(0.8) = x = 3,11 hours
