Practice variation 1 of 3
Differential equation — Coffee cooling with sketch
Your question
Coffee at is placed in a room that remains at . After minutes its temperature is , modelled by (do NOT prove this).
(i) After minutes, . By solving the differential equation, find when . Give your answer to the nearest minute.
(ii) Sketch the graph of as a function of .
This practice question was inspired by Question 12(b) in the 2021 NSW HSC Mathematics Extension 1 examination, © NESA. It is an original TestMum variation that practises the same mathematical idea, not an official NESA question.
Before you check
- Have you stated every choice or assumption?
- Can another student follow each line?
- Did you verify the final result independently?