Final answer:
To convert 15°C to Fahrenheit, you use the formula °F = (1.8 × °C) + 32, which gives you 59°F. A 40.0°F temperature drop equals approximately 22.22°C drop. The Celsius scale is called 'centigrade' because it has 100 degrees between the freezing and boiling points of water.
Step-by-step explanation:
To convert the temperature from degrees Celsius to degrees Fahrenheit, you can use the formula °F = (1.8 × °C) + 32. To find the temperature in degrees Fahrenheit when it is 15°C, you plug in the value of 15 for °C:
°F = (1.8 × 15) + 32
°F = 27 + 32
°F = 59
So, the temperature is 59°F. To answer another part of the question on how many degrees Celsius does the temperature decrease when there is a 40.0°F decrease in temperature, we can use the relation that any change in Fahrenheit degrees is nine-fifths the change in Celsius degrees.
Change in °C = (5/9) × (Change in °F)
Change in °C = (5/9) × 40°F
Change in °C = 22.22°C (approximately)
As for why the Celsius scale is sometimes called 'centigrade,' it's because the scale was historically defined by 100 degrees between the freezing and boiling points of water.