Question

At the moment a hot iron rod is plunged into freezing water, the difference between the rod's and the
water's temperatures is 100° Celsius. This causes the iron to cool and the temperature difference drops by
60% every second.
Write a function that gives the temperature difference in degrees Celsius, D(t), t seconds after the rod
was plunged into the water.​

Answer 1

Answer:

The function is

$D(t) = 100 \times( \frac{40}{100} )^{t}$

Step-by-step explanation:

At t = 0 the difference is 100 degree celsius.

After one second the temperature difference will be $100 - \frac{100\times60}{100}$ = $100(1 - \frac{60}{100} )$

After two second, the difference will be $100(1 - \frac{60}{100} )(1 - \frac{60}{100} ) = 100(1 - \frac{60}{100} )^{2}$

Hence, it can be written that,

$D(t) = 100 \times(1 - \frac{60}{100} )^{t}$ = $100 \times( \frac{40}{100} )^{t}$

Answer 2

Answer:

D(t)=100(0.4)^t

Step-by-step explanation: