Factors affecting friction
The intensity of friction depends on following factors: i) The area involved in friction. ii) The pressure applied on the surfaces. Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
Methods to reduce friction
i) Polish the contact surface. ii) Put oil or grease so that it fills in the small gaps of the flat parts. iii) Use ball bearings to reduce area of contact between rotating parts.
Lubrication
Following methods can be used to reduce friction: Oil is either thin or viscous. It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
To solve this problem we will apply the concepts related to the momentum.
This is defined as the product between the change in velocity and the mass of the object, that is


Where,
m = mass
Final velocity
Initial velocity
Our values are given as,
m = 14kg
= 11m/s
<em>the negative Symbol implies that the direction is opposite to the initial one and therefore there is also a change in the sense of magnitude</em>



The negative symbol indicates that the momentum has a direction opposite to that of the initial velocity. Or failing that, it has the same direction of the final speed
Answer:
use the formula
Explanation:
F = 1/ T
where F stands for frequency and T stands for period
sub in 3 Hz into frequency
3 = 1/T
0.333 = T
or in a fraction form
1/ 3
hope this helps
Increase because kinetic energy is all about the speed of an object and the more speed the more kinetic energy.