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3 years ago

The half-life of bismuth is 5 days. How much of a 100 gram sample will remain after 20 days?

1 answer:

8 0

Half-life is the duration needed for a compound to decay into half of its initial weight. In this case, the initial weight is 100gram. The calculation for the final weight should be:

final weight= initial weight * (1/2)^(duration/half-life)
final weight= 100 grams * (1/2)^(20days/5 days)
final weight= 100 grams * (1/2)^(4)
final weight= 100 * 1/16= 100/16 gram= 6.25 grams

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With a force of 5 newtons, Amanda pushes the stack of books to the right. At the same time, Jeremy, her little brother, pushes t

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Answer:

A. 5 N to the left

Note: The question is incomplete. The complete question is given below:

With a force of 5 newtons, Amanda pushes the stack of books to the right. At the same time, Jeremy, her little brother, pushes the stack of books to the left with a force of 10 newtons.

What is the direction and magnitude of the resulting force?

A. 5 N to the left

B. 5 N to the right

C. 10 N to the right

D. 10 N to the left

Explanation:

Forces are vector quantities.

Vector quantities are quantities that can be represented both in magnitude and direction.

Forces have both magnitude and direction. Forces can be directed positively or negatively.

For example, in the question above, if forces acting to the right are considered to be in the positive direction, forces acting to the left are considered to be acting in a negative direction.

In the addition of forces, both their magnitude and direction are taken into consideration.

In the example above, taking forces acting to the right as positive and to the left as negative, the sum of the forces is:

Resultant force, F = (5 N) + (-10N)

F = -5 N

Therefore, the net force is 5 N and is directed towards the left

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Answer:

Explanation:

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Answer:

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