Answer:
....se attachment
Perimeter =2(length+width)
we calculate the length
ADC right triangle in D
AC = diagonal: 13cm
AD = width: 5cm
pythagoras to calculate DC
DC²=AC²-AD²
DC²= 13²-5²
DC=√144 = 12cm
we calculate the perimeter:
P=2(12+5)=2*17=34cm
Step-by-step explanation:
in. when x=8 in.
Answer:
y= 2x
Step-by-step explanation:
To figure out what the equation would be you would set up an equation..
16 = 8z
Then you find z
16/8 = 8z/8
2 = z
Now you can set up a variable expression although it isn't necessary
y = zx
Now you plug in the value of z to complete the equation
y= 2x
I hope this is what you wanted!!!
2) After how many minutes will the coffee be 100 degrees?
The temperature of the coffee after 16 minutes is 134 degrees and after 1.3 minutes the coffee be 100 degrees.
A differential equation is an equation that contains one or more functions with its derivatives.
A cup of coffee at 181 degrees is poured into a mug and left in a room at 66 degrees.
After 6 minutes, the coffee is 139 degrees.
Assume that the differential equation describing Newton's Law of Cooling is (in this case) dT/dt=k(T-66).
T=∫k(t-66)dt
=k(t²/2-66)+c
When t=0 and T=181
181=k(0-66)+c
181=-66k+c
when t=6, T=139
139=k(6²/2-66)+c
139=-48k+c
-42=-18k
Divide both sides by 18
k=7/3
139=-48×7/3+c
c=139+112=251
T=7/3(t-66)+251
The temperature of the coffee after 16 minutes
T=7/3(16-66)+251
T=7/3(-50)+251
T=134 degrees
After how many minutes will the coffee be 100 degrees
100=7/3(t-66)+251
100=7/3t-7/3(66)+251
100=7/3t-154+251
100=7/3t+97
100-97=7/3t
3=7/3t
9/7=t
1.3=t
Hence, the temperature of the coffee after 16 minutes is 134 degrees and after 1.3 minutes the coffee be 100 degrees.
To learn more on Differentiation click:
#SPJ5
Answer:
Step-by-step explanation:
Answer:
The balance in the account at the beginning of last year was $181.
Step-by-step explanation:
Consider the provided information.
A savings account earns simple interest at a rate of 6% per year.
6% can be written as: 6/100=0.06
Last year the account earned $10.86 in interest.
Let the amount invested is represented by x.
Hence, the balance in the account at the beginning of last year was $181.
In this case, you have to find out the number whose 6% is 10.86.
So, Let the number be x.
x * 6/100 = 10.86
x * 6 = 1086
x = 181.
So, the account balance at the beginning of last year was $181.
Did you understand?