A certain radioactive material follows the law of exponential change and has a half-life of 38 hours. Find how long it takes for 90% of the radioactivity to be dissipated?
a. A certain radioactive material follows the law of
exponential change and has a half-life of 38
hours. Find how long it takes for 90% of the
radioactivity to be dissipated?
b. A thermometer reading 75o F is taken out
where the temperature is 20oF. The reading is
30oF 4 minutes later. Find the thermometer
reading 7 minutes after the thermometer was
brought outside.
c. An inductance of 2 henries and a resistance of
20 ohms are connected in series with an emf
of E volts. If the current is zero at time, t = 0,
find the current at the end of 0.01 sec if E =
100sin150t volts.
d. A tank originally contains 380 liters of brine
holding 450 g of dissolved salt. 8 liters/min of
brine containing 3.75 g/L of salt enters the tank
and the mixture assumed uniform leaves the
rate of 12 L/min. Determine the amount of salt
after 10 min.
Step by step
Solved in 2 steps
