Two thousand ounces of a radioactive substance are stored in a radioactive container. The amount in the substance that left is after t years can be modeled by equation y=200e^-0.00043t. Where y is the amount of substance left after t years. Approximately how many years will it take until 50 ounces of this substance remains? А
58 years
B
1,196 years
C
3,725 years
D
8,579 years

picture below

7.9m and 4.3°

step-by-step explanation:

let east be +x and north be +y, x = distance * cos θ, y = distance * sin θ  

for 3.5 south, y = -3.5  

for 8.2, x = 8.2 * cos 30 and y = 8.2 * sin 30  

for 15 west, x = -15  

total x = 8.2 * cos 30 – 15 ≈ -7.9  

total y = -3.5 + 8.2 * sin 30 = 0.6  

magnitude = [(8.2 * cos 30 – 15)^2 + 0.6^2)]^0.5  

the magnitude is approximately 7.9 m  

tan θ = y/x = 0.6/-7.9  

the angle is approximately 4.3˚ north of west