Question

On a cold February morning, the temperature of the radiator fluid in Stanley’s car is . When the engine is running, the temperature of the fluid goes up per minute. Approximately how long will it take before the radiator fluid temperature reaches ?

Answer 1

18.18 min

Explanation:

The complete question is

On a cold February morning, the radiator fluid in Stanley’s car is -18F. When the engine is running, the temperature goes up 5.4 F per minute. Approximately how long will it take before the radiator fluid temperature reaches 80 F?

The initial temperature of the engine
`T_(1)` = -18 F

rate of increase in temperature r = 5.4 F/min

Final temperature
`T_(2)` = 80 F

Difference in temperature ΔT =
`T_(1) -T_(2)` = 80 - (-18) = 98 F

time taken to reach this 80 F will be = ΔT/r

where ΔT is the difference in temperature

r is the rate of change of temperature

time taken = 98/5.4 = 18.18 min