A radioactive substance decays exponentially. A scientist begins with 140 milligrams of a radioactive substance. After 25 hours, 70 mg of the substance remains. How many milligrams will remain after 35 hours

Therefore 53.05 mg will remain of the given radioactive substance after 35 hours.

Step-by-step explanation:

Radioactive Decay:

Integrating both sides

                 [ ]

When t=0, = initial amount

Therefore the decay equation is

Given that, = Initial amount of the radioactive substance= 140 mg

After 25 hours, 70 mg of substance remains.

N= 70 mg, t=25 hours

               [  ]

The decay equation becomes

Now putting t= 35

   = 53.05 mg

Therefore 53.05 mg will remain of the given radioactive substance after 35 hours.

10.416 meters per second

step-by-step explanation:

distance=1 00 meters

time= 9.6 seconds in decimal form or 9 3/5 as a mixed number

average speed= 100/9.6

=10.416 meters per second or 10 52/125 as a mixed number.

if farmer matt works for 8 hours a day, how many days will it take him to completely plant 12 rows of crops? each batch of cookies needs 3/4 cups of sugar.

step-by-step explanation: