56.7 should be the right answer
Answer: 41.5 min
Step-by-step explanation:
This problem can be solved with the Radioactive Half Life Formula:
(1)
Where:
is the final amount of the radioactive element
is the initial amount of the radioactive element
is the time elapsed
is the half life of the radioactive element
So, we need to substitute the given values and find
from (1):
(2)
(3)
(4)
Applying natural logarithm in both sides:
(5)
(6)
Clearing
:
This is the time elapsed
Answer:
0.311 miles
Step-by-step explanation:
Convert 16 seconds to hours :
16 /60×60
= 16÷3600
= .004444hrs
Distance = Speed × time
= 70 × 0.00444444
= 0.311 miles
Answer:
145 yd²
Step-by-step explanation:
There will be dour triangular faces. For a triangle, area is given as
A=½bh where b is base and h is height. The base will be 5 yards and h is 12 yards hence for one triangular face, area will be ½*5*12=30 yd²
Since they are four similar triangles, area of triangular faces will be 30*4=120 yd²
The surface area of a square base is given by
A=a*a=a² where a is the dimension of one side. Given that the meaurement is 5 yards then A=5²=25 yd²
Total area will be the sum of triangular and square faces hence 120+25=145 yd²
Answer:do u mean divided 2?, then the answer is 325
Step-by-step explanation:650/2