Answer:
B
Explanation:
Friction is a force that opposes motion between any surfaces that are touching. Friction occurs because no surface is perfectly smooth Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Answer:
<em>A = 6.9 cm</em>
Explanation:
<u>Simple Harmonic Motion</u>
A mass-spring system is a common example of a simple harmonic motion device since it keeps oscillating when the spring is stretched back and forth.
If a mass m is attached to a spring of constant k and they are set to oscillate, the angular frequency of the motion is

The equation for the motion of the object is written as a sinusoid:

Where A is the amplitude.
The instantaneous speed is computed as the derivative of the distance

And the maximum speed is

Solving for the amplitude

Computing w

Calculating A


No force contributes to density, the density is a physical quantity that is defined as being

the raport between the mass of the object and its volume. However if you want to measure the density of an object you might want to determine its gravity force (weight)

from which knowing the gravitational acceleratin you can find its mass
where

is given in Newtons and

is given in
The quantity of matter in a body regardless of its volume or of any forces acting on it.