Answer:
81 cm square
Step-by-step explanation:
Answer z=2
See picture attached for the math
Answer:
76.25°
Step-by-step explanation:
The solution to the differential equation is an exponential curve with a horizontal asymptote at Tm. It passes through (0, 145) and (30, 95), so the equation can be written as ...
T = 80 +65((95-65)/(145-65))^(t/30)
T = 80 +65(3/8)^(t/30)
That is, the temperature difference is reduced to 3/8 of its original value in 30 minutes.
Since the coffee in cup B cools twice as fast, it will cool to the same temperature (95°) in 15 minutes. In the next 15 minutes, the temperature difference will be reduced to (3/8)^2 of the original 80°, so will be 11.25°. That is, the temperature of cup B will be ...
11.25° +65° = 76.25°
after 30 minutes.
Answer:
The magnetic field is
Direction is inward
Step-by-step explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
The radius of BC is 
The radius of DA is 
The length of CD is 
The length of AB is 
The current is 
The magnetic field is mathematically represented as

![B = \frac{\mu_o I}{4 \pi } [ \frac{\theta_{DA}}{r_{DA}} + \frac{\theta_{BC}}{r_{BC}}+ \frac{\theta_{CD}}{r_{CD}}+\frac{\theta_{AB}}{r_{AB}}]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%5Cmu_o%20I%7D%7B4%20%5Cpi%20%7D%20%5B%20%5Cfrac%7B%5Ctheta_%7BDA%7D%7D%7Br_%7BDA%7D%7D%20%2B%20%5Cfrac%7B%5Ctheta_%7BBC%7D%7D%7Br_%7BBC%7D%7D%2B%20%5Cfrac%7B%5Ctheta_%7BCD%7D%7D%7Br_%7BCD%7D%7D%2B%5Cfrac%7B%5Ctheta_%7BAB%7D%7D%7Br_%7BAB%7D%7D%5D)
Where

Where 

so
![B = \frac{\mu_o I}{4 \pi } [ \frac{\frac{2\pi}{3} }{0.20} - \frac{\frac{2\pi}{3}}{0.30}}+ \frac{0}{0.10}+\frac{0}{0.10}]](https://tex.z-dn.net/?f=B%20%3D%20%20%5Cfrac%7B%5Cmu_o%20I%7D%7B4%20%5Cpi%20%7D%20%5B%20%5Cfrac%7B%5Cfrac%7B2%5Cpi%7D%7B3%7D%20%7D%7B0.20%7D%20-%20%5Cfrac%7B%5Cfrac%7B2%5Cpi%7D%7B3%7D%7D%7B0.30%7D%7D%2B%20%5Cfrac%7B0%7D%7B0.10%7D%2B%5Cfrac%7B0%7D%7B0.10%7D%5D)

The direction is into the page
This because the magnitude of the magnetic field due to arc BC whose direction is outward is less than that of DA whose direction is inward
This is because according to Fleming's Left Hand Rule the direction of current is perpendicular to the direction of magnetic field so since current in arc BC and DA are moving in opposite direction their magnetic field will also be moving in opposite direction