Differential equations (40 pts) Consider a certain radioactive isotope sample with an initial mass, M0. It is observed that the mass of radioactive sample decays with time. The rate of mass decay at time t is proportional to the mass M(t) at that moment. The constant of proportionality is the decay rate constant, r > 0. The rate of mass decay is given by dM(t) dt = −rM(t). (1) (a) (20 pts) Solve the differential equation (1) to determine the mass of the sample at a given time.

If the thermal strain developed in polyimide film during deposition is given as 0.0044. assume room temperature is kept at 17.3 c, and thermal coefficient of expansion for the film and the substrate are 54 x 10^-6c^-1 and 3.3 x 10^-6c^-1respectively. calculate the deposition temperature.

Ajournal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. the bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. the bushing is 2.8 in long and supports a 700-lbf load. the journal speed is 900 rev/min. find the minimum oil film thickness and the maximum film pressure for both sae 20 and sae 20w-30 lubricants, for the tightest assembly if the operating film temperature is 160°f. a computer code is appropriate for solving this problem.

Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.