The answer to this question is A.
Answer:
0.903 seconds
Explanation:
To find how many seconds the acorn fall, we can use the formula for distance travelled with constant acceleration:
D = Vo*t + a*t^2/2,
where D is the distance travelled, Vo is the inicial speed, t is the time and a is the acceleration.
In our problem:
Vo = 0,
a = g = 9.81 m/s2,
D = 4 meters.
So, we can solve the equation to find the time:
4 = 0*t +9.81*t^2/2
4.905*t^2 = 4
t^2 = 4/4.905 = 0.8155
t = 0.903 seconds
I would say Option B) because Option C) is wrong since matter cannot be created. A closed system does not exchange matter so it's not Option D). Since an island is an isolated area, Option A) is wrong.
Answer: 1000 Hz
Explanation:
You can calculate frequency by dividing velocity by wavelength
Frequency = velocity/wavelength
Find velocity first.
900 m/3 s = 300 m/s
Plug values in to find frequency.
F = (300 m/s)/0.3 m
F = 1000 Hz
