4%
To find the percentage, first find the area of both circles. The area formula is

. After finding the area of the center of the target (19.625) and the area of the large target (490.625), set up a percent proportion to determine the percentage that the center takes up:


Cross multiplying and dividing by 490.625 will give a total of 4%.
Answer:
Scientist's do just general things anyone else would do to solve a problem.
Step-by-step explanation:
Scientists use their senses to observe
Scientists measure things, including distances, and weights.
Scientists also communicate their findings with other scientists and with the public.
If you have any questions feel free to ask in the comments.
Answer:
Airplane #1 equation: y=5/13x+42/13
Airplane #2 equation: y=1/3x+14
Step-by-step explanation:
So to find the slope of each airplane, you use the formula y2-y1/x2-x1. That means, for airplane#1 the equation will be 9-4/15-2. Simplify this and get 5/13. Then, for airplane#2, the equation will be 12-9/6-15. Simplify this and get 3/-9 and divide each side by 3 to get 1/-3 or -1/3. Next, use point slope formula to find the system of linear equations. Point slope formula is y-y1=m(x-x1). M is the slope. Use any point from the line. In this case, I will use (2,4). Tat means the first airplane's equation would be y-4=5/13(x-2). Then y-4=5/13x-10/13. Then, convert four into a fraction with a denominator of 13. This means, you have to multiply 4 by 13 to get 52/13. Add 52/13 to -10/13 to get 42/13. That means the first equation will be y=5/13x+42/13. The second equation point will be (6,12). This means the equation will be y-12=-1/3(x-6). Simplify this to get y-12=-1/3x+2. Simplify this to get y=1/3x+14. Therefore, Airplane#1 equation will be y=5/13x+42/13 and airplane #2 equation will be y=1/3x+14.
Hope this helps
Answer:
ΔT = ΔT0 e^-K T
As I understand Newton's Law of Cooling
ΔT at any time is the difference between the temperature and the surroundings
Originally ΔT0 = 95 - 22 difference between 95 and room temperature
65 - 22 = 33 = 73 e^-KT where t is time to cool to 65 deg
ln (33/73) = -KT K = .794 / 5 = .159 where 5 is time to cool to 65 deg
40 - 22 = 73 e^-.159 T where t is time to cool to 40 deg
18 = 73 e^-.159 T
ln (18 / 73) = -.159 T
T = 8.8 min
It would take 8.8 min for the object to cool to 40 deg C
Suppose the object cooled from 95 to 90 deg, then
ln 68 / 73 = -.159 T and T = .45 min
I think 33.3% that he Chooses that