No. A mirror works because of reflection.
By compressing the spring a distance <em>x</em> (in m), you are storing 1/2 <em>k</em> <em>x</em> ² (in J) of potential energy, which is converted completely into kinetic energy 1/2 <em>m v</em> ², where
• <em>k</em> = 40 N/m = spring constant
• <em>m</em> = 10 kg = mass of the ball
• <em>v</em> = 2 m/s = ball's speed (at the moment the spring returns to its equilibrium point)
So we have
1/2 <em>k</em> <em>x</em> ² = 1/2 <em>m</em> <em>v</em> ²
<em>x</em> = √(<em>m</em>/<em>k</em> <em>v</em> ²) = √((10 kg) / (40 N/m) (2 m/s)²) = 1 m
Answer:
It would take approximately 289 hours for the population to double
Explanation:
Recall the expression for the continuous exponential growth of a population:

where N(t) measures the number of individuals, No is the original population, "k" is the percent rate of growth, and "t" is the time elapsed.
In our case, we don't know No (original population, but know that we want it to double in a certain elapsed "t". We also have in mind that the percent rate "k" would be expressed in mathematical form as: 0.0024 (mathematical form of the given percent growth rate).
So we need to solve for "t" in the following equation:

Which can be rounded to about 289 hours
The stroke that begins a point in volleyball is called a serve