Aradioactive substance has a decay rate of 0.073 per minute. how many grams of a 120 gram sample will remain radioactive after 30 minutes? round the answer to the nearest tenth of a gram, and do not include the unit in your answer.

13.4 grams of a 120 gram sample will remain radioactive after 30 minutes.

Step-by-step explanation:

Given : A radioactive substance has a decay rate of 0.073 per minute.

To find : How many grams of a 120 gram sample will remain radioactive after 30 minutes?          

Solution :

Using decaying formula,  

Where, is the initial amount

r=0.073 is the decay rate

t=30 minute is the time

Substitute the value in the formula,

Therefore, 13.4 grams of a 120 gram sample will remain radioactive after 30 minutes.

3 ft

step-by-step explanation:

since the triangle is right use pythagoras' identity to solve for a

the square on the hypotenuse is equal to the sum of the squares on the other two sides, that is

a² + 8² = ( )²

a² + 64 = 73 ( subtract 64 from both sides )

a² = 9 ( take the square root of both sides )

a = = 3