Answer:

Explanation:
given,
length of ladder = 10 ft
let x be the distance of the bottom and y be the distance of the top of ladder.
x² + y² = 100
differentiating with respect to time we get
..............(1)
when x = 8 and y = 6 and when \dfrac{dx}{dt} = 1.4ft/s
from equation (1)
now,


let the angle between the ladders be θ

y = xtan θ




Answer:
The the quality of the refrigerant at the exit of the expansion valve is 0.179.
Explanation:
Given that,
Initial pressure = 10 bar
Temperature = 22°C
Final pressure = 2.0 bar
We using the value of h

The refrigerant during expansion undergoes a throttling process
Therefore, 
We need to calculate the quality of the refrigerant at the exit of the expansion valve
At 2.0 bar,
The property of ammonia


Using formula

Put the value into the formula



Hence, The the quality of the refrigerant at the exit of the expansion valve is 0.179.
an electric current is a flow of electric charge in electric circuits this is carried by moving electrons in a wire and an electric circuit is an electrical network of electrical components and model of interconnection consisting electrical elements
Let the cold water go up x degrees.
Let the hot water go down 100 - x degrees.
The formula for heat exchange is m*c*delta t
Givens
Ice
deltat = x
m = 0.50 kg
c = 4.18
Hot water
deltat = 100 - x
m = 1.5 kg
c = 4.18
Formula
The heat up = heat down
0.50 * c * x = 1.5 * c * (100 - x) Divide both sides by c
Solution
0.50 *x = 1.5*(100 - x) Remove the brackets.
0.5x = 150 - 1.5x Add 1.5x to both sides.
0.5x + 1.5x = 150 - 1.5x + 1.5x Combine like terms
2x = 150 Divide by 2
x = 75
Answer
A
B)is pills everything to the surface of the earth not sure about A