Question

The temperature at 12 noon was 10°C above zero. If it decreases at the rate of 2°C/h until midnight, at what time would the temperature be 8°C below zero. What would be the temperature at midnight?

Answer is = 9 p.m. and -14°C

Give me the answer with solution and statement​

Answer 1

Step-by-step explanation:

The temperature at 12 noon = 10° C above zero

The temperature is decreasing at 2° C per hour

8° C below zero = – 8° C

So, total fall in temperature from 10° C to 0° C and from 0° C to – 8° C = 18° C

Since the temperature falls 2° C in every one hour.

Therefore, to decrease 18° C, time taken = 18/2 = 9 hours

Present time is 12 noon so, the time when the temperature is – 8° C= 12 noon + 9 hours

So, The time at which the temperature will be – 8° C = 9 PM

At 9 PM, the temperature is – 8° C, the temperature at 12 midnight will be =

(- 8° C) + (- 2° C × 3 hours)

= (- 8° C) + (- 6° C)

= – 14° C

So, at 12 midnight the temperature will be – 14° C.