Question

12) The temperature at 12 noon was 10% above zero. If it decreases at the rate of 2'c per hour
until midnight, at what time would the temperature be 8°C below zero? What would be the
temperature at mid-night?​

Answer 1

Answer:

since the temperature falls 2o c in every 1 hour so at midnight that temperature will be -14o c night

Answer 2

ANSWER -

-14°c

EXPLANATION-

At 12 noon, the temperature =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

=12noon+9hours

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

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

(−8°C)+(−2°C×3hours)

=(−8°C)+(−6°C)

=−14°C

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