Answer:
The heating element of the heater is made up of alloy which has very high resistance so when current flows through the heating element, it becomes too hot and glows red. But the resistance of cord which is usually of copper or aluminum is very low so it does not glow.
<h3><u>Answer;</u></h3>
A.75°C
<h3><u>Explanation</u>;</h3>
Let the change in temp of cold water be x degrees,
while that of hot water be 100 - x degrees.
Heat exchange = mcΔt
Ice
Δt = x
m = 0.50 kg
c = 4.18 kJ/kg*°C
Hot water
Δt = 100 - x
m = 1.5 kg
c = 4.18
But;
Heat lost = heat gained
0.50 * c * x = 1.5 * c * (100 - x)
0.50 *x = 1.5*(100 - x)
0.5x = 150 - 1.5x
0.5x + 1.5x = 150 - 1.5x + 1.5x
2x = 150
x = <u>75° C</u>
Hence; the equilbrium temperature will be 75° C
Whether a line is "steep" or "shallow" depends on the slope of the line. In the equation y=mx+b, m is the slope. In your first equation, 1/2x+4, the slope would be 1/2 which means there is 1 increase in the vertical, or y, value for each 2 increases in the horizontal, or x value. This line would be shallow.