Q2/ ANSWER ONE OF THE FOLLOWING (A OR B) (25% Marks) (A)For a bar of length 1 m subjected to heat of boundary conditions u(0,+)=50°C, au/ax(1,+)=0°C. If the initial temperature is u(x,0)-50(1+x), find the solution after three time intervals (3A+) using EXPLICIT METHOD, where Ax=0.25m, ди ди a.Mt = 0.5. at Ar² 1m

Q8) A body is cooling in surroundings maintained at 10. Its temperature after t minutes is given by: de k·(0 – 10) where kis a constant. If the temperature of the body is initially 70°C %3D dt and 10minutes later is 40"C (a) Find k (b) Find the body's temperature after further 15 minutes.

A 1000 L tank contains 500 L of water with a salt concentration of 10 g/L. Water with a salt concentration of 90 g/L flows into the tank at a rate of 80 L/min. The fluid mixes instantaneously and is pumped out at a specified rate Rout. Let y(t) denote the quantity of salt in the tank at time t. Find the salt concentration att = 10 min assuming that Rout 120 L/min. (Use decimal notation. Give your answer to one decimal place.) the concentration of salt : g/L

In a natural habitat, the population of a certain species of snails is given by P=0.8(Ae* +500), where A and k are constants and / is the time in years starting from 1 January 2010. Over a period of 8 years from 1 January 2010 to 31 December 2017, the population decreased from 50 000 to 19 000. (i) Calculate the valucs of A and of k.