Answer:
9.22 s
Explanation:
One-quarter of a turn away is 1/4 of 2π, or π/2 which is approximately 1.57 rad
Let t (seconds) be the time it takes for the child to catch up with the horse. We would have the following equation of motion for the child and the horse:
For the child: 
For the horse: 
For the child to catch up with the horse, they must cover the same angular distance within the same time t:
t = 25.05 or t = 9.22
Since we are looking for the shortest time we will pick t = 9.22 s
Answer:
t=1.623 sec
Explanation:
The distance traveled before the echo is had is:
Given the speed of sound as v=345m/s, we use the speed equation to solve for t:
Hence, it takes 1.623 seconds to hear the echo.
Answer:
The right solution is "165.8 nm".
Explanation:
Given:
Index of refraction,
n = 1.81
Wavelength,
λ = 600 nm
We know that,
⇒ 
By putting the values, we get
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
