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
I believe the answer is b) slowly heating the surface
Answer:
2.2 m/s^2
Explanation:
Acceleration = Force / Mass
= 7.92 / 3.6 = 2.2m/s^2
Hope this help you :3
<span>force applied causes movement of an object in the same direction as the applied force.</span>
Electronegativity is the measure of the tendency of an atom to attract a bonding pair of electrons. In the periodic table, electronegativity increase across the period because the charges on the nucleus increase. The correct arrangement for the atoms given above is as follows
Flourine and Francium
Chlorine and Cesium
Nitrogen and Sodium
Phosphorus and Lithium
Nitrogen and Sulphur.