Some of these frictions depend on the Pressure, temperature of atmosphere.
Static Friction: This is the friction force when two objects in contact are not moving relative to each other. This friction is higher than kinetic friction.
Kinetic or Dynamic friction: this the friction force opposing the motion of objects, when two objects in contact are in motion relative to each other. It is less than the static friction. The two surfaces are rubbing against each other as they move.
Rolling friction: This is the friction when two objects are in contact and one object is rolling over the other - like a wheel on a road. The point of contact appears as stationary. The rolling friction is very less compared to static friction & dynamic friction.
Lubricated friction: this is the friction between two solid surfaces in contact with a layer of lubricant fluid flowing in between them. This friction is the least.
Fluid friction - viscosity : this is friction between two adjacent layers that are moving relative to each other at different speeds in a fluid. This is not high.
Internal friction: when an object is compressed and forced to deform, like in a piece of rubber, there is friction between the layers, that opposes this deformation.
Skin friction is the friction that opposes movement of a fluid across a solid surface. This is also called drag. When a coin is dropped in water, there is a friction called drag on the coin. Same is the case when a ball is thrown, a drag is experienced by the ball due to the drag of air.
Hot water, as in very hot water, goes to steam with an enormous change in volume and pressure. This is capable of driving turbine blades, which in turn rotate enormous copper (eg) wired coils in enormous magnetic fields. This in turn produces electricity via electromagnetic induction and Fleming's right hand (I think it is) DYNAMO rule. That goes down miles and mile of v heavy conducting wire/cable as electricity.
Use the right equation. To calculate the normal force of an object at an angle, you need to use the formula: N = m * g * cos (x) For this equation, N refers to the normal force, m refers to the object's mass, g refers to the acceleration of gravity, and x refers to the angle of incline.
Answer:
h = 20 m
Explanation:
given.
height, h = 10 m
Potential energy at 10 m = 50 J
Kinetic energy at 10 m = 50 J
maximum height the ball will reach, H = ?
Total energy of the system
T E = 50 J + 50 J
T E = 100 J
now,
A h = 10 m
P E = m g h
50 = m g x 10
mg = 5 ..............(1)
at the top most Point the only Potential energy will be acting on the body.
now, TE = Potential energy
100 = m g h
5 h = 100
h = 20 m
hence, the maximum height reached by the ball is equal to 20 m.
<h3><u>Answer;</u></h3>
1 × 10^-8 M
<h3><u>Explanation</u>;</h3>
pH is given by the -log[H+] while
pOH is given by the -log[OH-]
But;
pH + pOH = 14
Thus; if pH is 6, then pOH = 8
pOH = 8
-log[OH-] = 8
[OH-] = 10^-8 M
The concentration of OH- ions at a pH of 6 is 1 × 10^-8 M
