The mass of a radioactive element decays at rate given by m(t) = m0e-rt, where m(t) is the mass at any time t, m0 is the initial mass, and r is the rate of decay.

Uranium-240 has a rate of decay of .0491593745. What is the mass of U-240 left after 10 hours, if the initial mass is 50 grams?
A)
28.54387 g
B)
30.58254 g
C)
32.14286 g
D)
32.68034 g

Question

The mass of a radioactive element decays at rate given by m(t) = m0e-rt, where m(t) is the mass at any time t, m0 is the initial mass, and r is the rate of decay.

Uranium-240 has a rate of decay of .0491593745. What is the mass of U-240 left after 10 hours, if the initial mass is 50 grams?
A)
28.54387 g	
B)
30.58254 g	
C)
32.14286 g	
D)
32.68034 g

p0sitr0n · Answer

in the formula, what are the units of mass and what are the units of time for your rate?