The answer is A. 1000 Hz.

10 Hz is the frequency of industrial air conditioners; they're very low pitched.

.1 Hz is extremely low. No way could we hear that...though we might be able to see it in, say, the waves of an ocean.

100000 Hz is extremely high. I'm not sure if many organisms can hear that.

**Answer:**

exercise dailyyy

Help you control your weight. ...

Reduce your risk of heart diseases. ...

Help your body manage blood sugar and insulin levels. ...

Help you quit smoking. ...

Improve your mental health and mood. ...

Help keep your thinking, learning, and judgment skills sharp as you age.

**Explanation:**

**Answer:**

F = 431671.31 [N]

**Explanation:**

This problem can be solved using the work and energy theorem, which tells us that the initial mechanical energy (potential energy + kinetic energy) plus the sum of the work from the initial position to the end will be equal to the final mechanical energy.

As the train stops at the end, the speed at Point 2 is equal to zero,so we can determine the work, we first convert the speed from [km/h] to meters per second.

The negative sign means that the work is done in the opposite direction to the movement.

Knowing the work we can calculate the force, since an initial input data is the distance

W = F * d

F = W / d

F = (2080.66*10^6) / 4820

F = 431671.31 [N]

15 explanation: look at the graph