Answer: 217.52 N
Explanation: The applied force is 20 N, the distance covered is 12.0 m and the angle is 25° above the horizontal.
Hence the formulae that defines work done is given by
W = Force × distance
But since the force has been inclined at an angle θ above the horizontal, the horizontal component of force is neccesary to produce the required motion to make the child do work on the wagon.
Hence
Work done = (horizontal component of force) × distance
Work done = F cos θ × distance
Work done = 20 cos 25 × 12 = 217.52 N
<h2>
Answer: The half-life of beryllium-15 is 400 times greater than the half-life of beryllium-13.</h2>
Explanation:
The half-life 
of a radioactive isotope refers to its decay period, which is the average lifetime of an atom before it disintegrates.
In this case, we are given the half life of two elements:
beryllium-13: 
beryllium-15: 
As we can see, the half-life of beryllium-15 is greater than the half-life of beryllium-13, but how great?
We can find it out by the following expression:
Where 
is the amount we want to find:
Finally:
Therefore:
The half-life of beryllium-15 is <u>400 times greater than</u> the half-life of beryllium-13.
An ice cube causes hot coffee to become cool because the amount of coldness contrasts the hot coffee to make it a little cooler
<span>The magnitude of the rock is equal to g. After the rock is released, there are no more forces acting on it, yet gravity remains. The initial inputs, on a bridge, at an angle of 30 deg below horizontal do not matter after the release.</span>
I believe it's D. The centripetal force moves away from the center, but the marble stays there due to the string.
