Complete question is;
A 10 cm thick grindstone is initially 200 cm in diameter, and it is wearing away at a rate of 50 cm/hr. At what rate is its diameter decreasing?
Answer:
Diameter is decreasing at the rate of 5/(2πr) cm/hr
Step-by-step explanation:
We are told the stone is wearing away at a rate of 50 cm/hr. This means the volume is decreasing. Thus;
dV/dt = -50 cm/hr
Now, a grindstone is in the shape of a cylinder. Thus, volume of grindstone is;
V = πr²h
dV/dr = 2πrh
Now,to find the rate at which the diameter is decreasing, we'll write;
dr/dt = (dV/dt)/(dV/dr)
dr/dt = -50/(2πrh)
We are given;
Diameter = 200 cm
Radius; r = 200/2 = 100 cm
Thickness; h = 10 cm
Thus;
dr/dt = -50/(2π × r × 10)
dr/dt = -5/(2πr) cm/hr
Y= 0.8x - 17
x= (y+17)/0.8
substituting y= 47 in the equation
x= (47+17)/0.8
x= 64/0.8
x=80
The variable I=f(w) represents the number of individuals (in thousands) infected w weeks after the epidemic begins.
The value of I=f(2) represents the number of individuals in thousandas infected 2 weeks after the beginning of the epidemic.
From the graph, where I=8, we can conclude that there are 8,000 infected people after 2 weeks of the beginning of the epidemic.
Answer:
f(2) = 8
Means 8,000 people are infected after 2 weeks of the beginning of the epidemic.
Answer:
6x
Step-by-step explanation:
3x/y=x/2y
Since 2y is 2X greater than y, 6x is 2X greater than 3x.
So,
The answer is 6x.
