The surface area SSS, in mm2\text{mm}^2mm2, of a metallic crystal growing in a laboratory environment is monitored over time. The surface area is modelled by the equation
log10S=0.85+0.072t \log_{10} S = 0.85 + 0.072t log10S=0.85+0.072twhere t t\,t is the time in hours after the crystal began to form.
Use the equation of the model to answer parts (a) and (b).
Find the initial surface area of the crystal, giving your answer to 2 decimal places.
After T T\,T hours, the surface area reaches 120 mm2. Find the value of TTT, giving your answer to 2 decimal places.
Practise Edexcel A Level Maths Exponential Models with exam-style questions for A Level Maths. 42 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
