Question

The temperature at bedtime was 20 degrees. 10 minutes later

is 16 degrees

If the temp continues to change at the same rate, how many minutes
until it reaches -8 degrees?

Answer 1

60 min from 16° to -8°

Explanation:

given that the temperature at bedtime was 20° . And 10minutes later it was 16° .

Change in temperature= 20-16 = 4°

time = 10min

rate of change of temperature= 4°/10min

again , initial temperature= 16°

final temperature= -8°

change in temperature= -8 -16 = -24°

time taken= 24 / 4 * 10 min = 60min

and we are done!

Answer 2

If the temperature continues to change at the same rate, it will take a further 60 minutes until it reaches -8 degrees.

Explanation:

To find the rate of change in temperature, divide the change in temperature by the time:

`\implies \sf Rate\;of\;change=(16^(\circ)C-20^(\circ)C)/(10\;min)=-0.4^(\circ)C/min`

Therefore, the rate of change is a decrease of 0.4 degrees per minute.

To calculate how many minutes it takes for the temperature to reach -8 degrees:

`\implies \sf Rate\;of\;change=(temperature\;change)/(time)`

`\implies \sf -0.4^(\circ)C/min=(-8^(\circ)C-16^(\circ)C)/(time)`

`\implies \sf Time=(-8^(\circ)C-16^(\circ)C)/(-0.4^(\circ)C/min)`

`\implies \sf Time=(-24^(\circ)C)/(-0.4^(\circ)C/min)`

`\implies \sf Time=60\;min`

Therefore, if the temperature continues to change at the same rate, it will take a further 60 minutes until it reaches -8 degrees.