Number of Bacteria.

. The number N of bacteria in a culture grew at a rate proportional to N. The value of N was initially 100 and increased to 332 in 1 hr. The governing equation is dN dt = log(3.32)N, N(0) = 100. What is the value of N at time t = 1.5 hr.

Answer 1

[Wan Ji]

Here you can use symbolic solution

syms N(t) t
eq = diff(N)==log(3.32)*N
N = dsolve(eq,N(0)==100)
N_1dot5_hour = eval(subs(N,t,1.5))

Result becomes

N_1dot5_hour =

     6.049327896551812e+02

So the value of N at time t = 1.5 hr is approximately 605.

[Image Analyst]

@Saumya Singh some professors use plagiarism detectors so be careful about submitting Wan Ji's solution as your own original work for your homework. If you get caught, you could be in trouble.

Answer 2

[CHIRAG PATEL]

If the growth rate of a culture of bacteria is proportional to the number of bacteria present and after 1 day is 1.25 times the original number, within what interval of time will the number of bacteria (a) double, (b) triple?