Newton's Law of Cooling
Tf=Ts+(Ti-Ts)e^(-kt) where Tf is temp at time t, Ts is temp of surroundings, Ti is temp of object/fluid. So we need to find k first.
200=68+(210-68)e^(-10k)
132=142e^(-10k)
132/142=e^(-10k)
ln(132/142)=-10k
k=-ln(132/142)/10
k≈0.0073 so
T(t)=68+142e^(-0.0073t) so how long until it reaches 180°?
180=68+142e^(-0.0073t)
112=142e^(-0.0073t)
112/142=e^(-0.0073t)
ln(112/142)=-0.0073t
t= -ln(112/142)/(0.0073)
t≈32.51 minutes
The volume of a sphere refers to the number of cubic units that will exactly fill a sphere. The volume of a sphere can be found or calculate by using the formula V=4/3πr^3, where r represents the radius of the figure.
In this exercise is given that a sphere has a radius of 4 centimeters and it is asked to find its volume and use 3.14 as the value of π or pi. The first step would be substitute the values into the previous mention formula.
V=4/3πr^3
V=4/3(3.14)(4 cm)^3
V=4/3)(3.14)(64 cm^3)
V=267.9 cm^3
The volume of the sphere is 267.9 cubic centimeters.
Answer:
i think the area is 21 srry if im wrong
Step-by-step explanation:
