Answer:
<em>The coefficient of static friction between the crate and the floor is 0.41</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in the air or rough surfaces, it loses acceleration and velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[1]
Where 
is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W = m.g
The crate of m=20 Kg has a weight of:
W = 20*9.8
W = 196 N
The normal force is also N=196 N
We can find the coefficient of static friction by solving [1] for :
The friction force is equal to the minimum force required to start moving the object on the floor, thus Fr=80 N and:
The coefficient of static friction between the crate and the floor is 0.41
According to the <u>Third Kepler’s Law of Planetary motion</u> “<em>The square of the orbital period of a planet is proportional to the cube of the semi-major axis (size) of its orbit”.</em>
In other words, this law states a relation between the orbital period 
of a body (moon, planet, satellite) orbiting a greater body in space with the size 
of its orbit.
This Law is originally expressed as follows:
<h2>
(1)
</h2>
Where;
is the Gravitational Constant and its value is 
is the mass of Jupiter
is the semimajor axis of the orbit Io describes around Jupiter (assuming it is a circular orbit, the semimajor axis is equal to the radius of the orbit)
If we want to find the period, we have to express equation (1) as written below and substitute all the values:
<h2>
(2)
</h2>
Then:
<h2>
(3)
</h2>
Which is the same as:
<h2>
</h2>
Therefore, the answer is:
The orbital period of Io is 42.482 h
Answer:
b. craters, river valleys feeding into surface lakes of very cold liquids
Explanation:
- Jovian moons are the four largest satellites like the moon of the Jupiter ie the Lo, Europa, Ganymede, Callisto and were first seen by the galileo. They are amiugly the largest moons with radii larger than the dwarf planet.
- Lo has more than 400 active volcanoes and dotted more than 100 mountains and has an extremely thin atmosphere made up of sulfur dioxide. The Europa has deep oceans of liquid water, and the layer of ice, and are characteristic of the tidal heating.
- <u>While the surface of Callisto is heavily cratered and has salty liquid water.</u>
In the process of peppering the question with those forty (40 !) un-necessary quotation marks, you neglected to actually show us the illustration. So we have no information to describe the adjacent positions, and we're not able to come up with any answer to the question.
Hiiiii friends......
here is your answer.....
✌✌ Resistive force is a force where direction is opposite to the velocity of body or the sum of the other force and may refer to friction
now force lost by the machine
