The frequency of any wave is (speed) / (wavelength).
Frequency = (330 m/s) / (2m) = 165 per second = <em>165 Hz</em>.
Period = 1 / frequency = 1 / (165 per second) = <em>0.0061 second </em>
<span>b) The force with a distance of 150 km is 889 N
c) The force with a distance of 50 km is 8000 N
This question looks like a mixture of a question and a critique of a previous answer. I'll attempt to address the original question.
Since the radius of the spherical objects isn't mentioned anywhere, I will assume that the distance from the center of each spherical object is what's being given. The gravitational force between two masses is given as
F = (G M1 M2)/r^2
where
F = Force
G = gravitational constant
M1 = Mass 1
M2 = Mass 2
r = distance between center of masses for the two masses.
So with a r value of 100 km, we have a force of 2000 Newtons. If we change the distance to 150 km, that increases the distance by a factor of 1.5 and since the force varies with the inverse square, we get the original force divided by 2.25. And 2000 / 2.25 = 888.88888.... when rounded to 3 digits gives us 889.
Looking at what looks like an answer of 890 in the question is explainable as someone rounding incorrectly to 2 significant digits.
If the distance is changed to 50 km from the original 100 km, then you have half the distance (50/100 = 0.5) and the squaring will give you a new divisor of 0.25, and 2000 / 0.25 = 8000. So the force increases to 8000 Newtons.</span>
To calculate the kinetic coefficient of friction is closest to: 1. 0.23.
<u>Given the following data:</u>
- Horizontal force = 4.5 Newton
To calculate the kinetic coefficient of friction:
Mathematically, the kinetic force is given by this formula;

<u>Where;</u>
represents the kinetic force.
is the normal force.
- μ represents the kinetic coefficient of friction.
Making μ the subject of formula, we have:

Substituting the given parameters into the formula, we have;

u = 0.225 ≈ 0.23
Read more on kinetic coefficient of friction here: brainly.com/question/13940648