Answer:
Ro = 7.8 [g/cm³]
Explanation:
According to the principle of Archimedes, the volume of a body immersed in a liquid is equal to the volume displaced by water. That is, in this problem The displacement volume is equal to the new volume minus the original volume.
![V_{n}=110[cm^{3} ]\\V_{o}=100[cm^{3} ]\\V_{d}=110-100 = 10 [cm^{3} ]](https://tex.z-dn.net/?f=V_%7Bn%7D%3D110%5Bcm%5E%7B3%7D%20%5D%5C%5CV_%7Bo%7D%3D100%5Bcm%5E%7B3%7D%20%5D%5C%5CV_%7Bd%7D%3D110-100%20%3D%2010%20%5Bcm%5E%7B3%7D%20%5D)
We now know that density is defined as the relationship between mass and volume.

where:
Ro = density [g/cm³]
m = mass = 78 [g]
Vd = displacement volume [cm³]
![Ro = 78/10\\Ro = 7.8 [g/cm^{3} ]](https://tex.z-dn.net/?f=Ro%20%3D%2078%2F10%5C%5CRo%20%3D%207.8%20%5Bg%2Fcm%5E%7B3%7D%20%5D)
Answer: The coefficient of kinetic friction is μ = 0.6
Explanation:
For an object of mass M, the weight is:
W = M*g
where g is the gravitational acceleration: g = 9.8m/s^2
And the friction force between this object and the surface can be written as:
F = W*μ
where μ is the coefficient of friction (kinetic if the object is moving, and static if the object is not moving, usually the static coefficient is larger)
In this case, the weight is:
W = 20N
And the friction force is:
F = 12N
Replacing these values in the equation for the friction force we get:
12N = 20N*μ
(12N/20N) = μ = 0.6
The coefficient of kinetic friction is μ = 0.6
Answer:
-223.64684 J
Explanation:
F = Force that is applied to the crate = 68 N
s = Displacement of the crate = 3.5 m
= Angle between the force and displacement vector = (180-20)
Work done is given by

The work that Paige does on the crate is -223.64684 J