<h2>
Mass of object in Earth is 1.37 kg</h2>
Explanation:
On planet B where the magnitude of the free-fall acceleration is 1.91g , the object weighs 25.74 N.
We have
Weight = Mass x Acceleration due to gravity
On planet B
25.74 = Mass x 1.91 g
25.74 = Mass x 1.91 x 9.81
Mass = 1.37 kg
Mass is constant for an object. It will not change with location.
Mass of object in Earth = Mass of object in Planet B
Mass of object in Earth = 1.37 kg
Answer:
7×160=1120kj so,1120kj=1.12j.
Explanation:
Energy is equal to force times distance,so we add all the distance and we multiply them with the total force of the spring to get the answer. However, the answer is in kilojoules so we have to change it in to joules by dividing the answer into joules by 1000..
Via half-life equation we have:

Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:

There is 6.25 grams left of Ra-229 after 12 minutes.