Answer:

Definition:
Half-life- The time taken for half of the radioactive isotopes to decay.
Explanation:
How does radioactive decay work? Radioactive decay is a process by which unstable nuclei become more stable through the emission of alpha or beta particles or gamma rays.
Since a half-life is the time taken for half of the isotopes to decay, we can simply divide the initial mass of 100 grams by 2; this gives us 50 grams.
1) Divide 100g by 2.

A truck is moving with less velocity in the direction in which the truck is moving earlier because the truck has more momentum.
<h3 /><h3>In which direction the truck moves?</h3>
A truck is moving with the velocity of 10 m/s in the same direction in which the truck is moving earlier because the truck has more mass so it has more momentum. Due to collision, the velocity of the truck is slow down but can't be stopped because of high momentum in the truck.
So we can conclude that a truck is moving with less velocity in the direction in which the truck is moving earlier because the truck has more momentum.
Learn more about momentum here: brainly.com/question/7538238
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Answer:
moon disappear because of the rotation