According to Ohm's law electrical potential difference (V) is directly proportional to the product of current (I) times resistance (R).
V = IR
Relationship between power (P) and the current and the voltage is
P = IV
Using the above equations can also be written
P = V2 / R
and
P = I 2 R
Showing posts with label physics formula. Show all posts
Showing posts with label physics formula. Show all posts
Sunday, October 16, 2011
Properties of Matter
Density
The mass of a substance in unit volume is density (D).
D = m / V
Measuring the density of substances is easier when compared to the density of other substances in the density of information. Water is used for this purpose. The ratio of the density of the substance in water is called specific gravity (SG) of the substance.
SG = Dsubstance / dwater
The density of water is 1000 kg/m3
Pressure
The pressure (P) is the force (F) per unit area (A)
P = F / A
The mass of a substance in unit volume is density (D).
D = m / V
Measuring the density of substances is easier when compared to the density of other substances in the density of information. Water is used for this purpose. The ratio of the density of the substance in water is called specific gravity (SG) of the substance.
SG = Dsubstance / dwater
The density of water is 1000 kg/m3
Pressure
The pressure (P) is the force (F) per unit area (A)
P = F / A
Gravitation
Kepler's laws
Towards the end of the sixteenth century, Tycho Brahe, has collected an enormous amount of information given accurate measurements of the position of the planets. Johannes Kepler, after a detailed analysis of the measures announced three laws in 1619.
1. Track every planet is an ellipse, which is the Sun in a colony.
Every second planet moves so that the line (imaginary) connecting to the Sun sweeps equal areas in equal times.
3. The squares of the periods of revolution of the planets around the sun are proportional to the cubes of their mean distances from it.
Newton's universal gravitation
Some fifty years after the laws of Kepler announced his name, Isaac Newton showed that each particle in the universe attracts every other with a force proportional to the product of their masses and inversely proportional to the square of their separation.
Therefore:
If F is the force of gravity-induced, g the acceleration of gravity, G the universal gravitational constant (6.67x10-11 N.m2/kg2), m the mass and r the distance between two objects. Then
F = G m1 m2 / R2
Towards the end of the sixteenth century, Tycho Brahe, has collected an enormous amount of information given accurate measurements of the position of the planets. Johannes Kepler, after a detailed analysis of the measures announced three laws in 1619.
1. Track every planet is an ellipse, which is the Sun in a colony.
Every second planet moves so that the line (imaginary) connecting to the Sun sweeps equal areas in equal times.
3. The squares of the periods of revolution of the planets around the sun are proportional to the cubes of their mean distances from it.
Newton's universal gravitation
Some fifty years after the laws of Kepler announced his name, Isaac Newton showed that each particle in the universe attracts every other with a force proportional to the product of their masses and inversely proportional to the square of their separation.
Therefore:
If F is the force of gravity-induced, g the acceleration of gravity, G the universal gravitational constant (6.67x10-11 N.m2/kg2), m the mass and r the distance between two objects. Then
F = G m1 m2 / R2
Circular motion
a= v2 / r
F = ma = mv2 / r
Work and energy
As we know the law of conservation of energy: energy is always conserved.
The work is a product of power, and during the trip, it moves. Imagine pushing a heavy box across the room. In addition to moving more work to do! If W is work, F the force acting around the corner? and s after the trip.
W = FsCos?
Energy comes in many forms. We see here is the kinetic energy (KE) and potential energy (PE)
Transitional KE = ½ mv2
Rotational KE = ½ I2
where I is the moment of inertia of the object (a simple way to understand the moment of inertia is to consider that the same mass during the transition KE)
Gravitational PE = mgh
where h is the height of the object
Elastic PE = kL 2 ½
where k is the spring constant (how it gives the spring will stretch to a strength of unity) and L is the length of the spring. Simple is not it!
The work is a product of power, and during the trip, it moves. Imagine pushing a heavy box across the room. In addition to moving more work to do! If W is work, F the force acting around the corner? and s after the trip.
W = FsCos?
Energy comes in many forms. We see here is the kinetic energy (KE) and potential energy (PE)
Transitional KE = ½ mv2
Rotational KE = ½ I2
where I is the moment of inertia of the object (a simple way to understand the moment of inertia is to consider that the same mass during the transition KE)
Gravitational PE = mgh
where h is the height of the object
Elastic PE = kL 2 ½
where k is the spring constant (how it gives the spring will stretch to a strength of unity) and L is the length of the spring. Simple is not it!
Laws of Motion
Newton's Laws of Motion
By Newton's second law, which says the acceleration of the body is directly proportional to the unbalanced net force and inversely proportional to body mass ratio is based on the force (F), mass (m) and acceleration (a). This is, of course, a wonderful relationship and a huge advantage.
F = ma
Knowing two quantities automatically gives you the third
Momentum
Momentum (p) is the moment of a body. A heavy body moves at a fast pace is hard to stop. A body of light at low speeds, on the other hand can be stopped easily. The momentum has to do with the mass and velocity.
p = mv
Often, the problems of physical force against before and after a collision. In this case, the total momentum of the bodies before the collision is taken equal to the amount of movement of the bodies after the collision. That is, the momentum is maintained.
2D & 3D Motion
Resolution of a vector
It is often necessary to divide a vector into its components. Dividing a vector into its components is called resolution of the vector. The initial vector is the result of these components. When the components of a vector is at right angles to each other, they are called the rectangular components of a vector.
It is often necessary to divide a vector into its components. Dividing a vector into its components is called resolution of the vector. The initial vector is the result of these components. When the components of a vector is at right angles to each other, they are called the rectangular components of a vector.
In the picture above the green vector is resolved into two vectors: the blue and red. These vectors are mutually perpendicular. Are the rectangular components of the vector Green.
Rectangular components of a vector
As the rectangular components of a vector are perpendicular to each other, we can do math on them. This allows us to solve many real-life problems. After all, the best of physics is that it can be used to solve real world problems.
Note: Since it is difficult to use the items on the vector processor computer to your word, we, our money notation. We'll show you all the vector quantities in bold. For example, "'is a scalar quantity, and" "is a vector.
Let Ax and Ay are the rectangular components of a vector A
Then
A = Ax + Ay means that the vector A is the resultant of vectors Ax and Ay
And 'the size of the vector and Ax and Ay are the magnitudes of the vectors Ax and Ay
As we deal with rectangular components are at right angles to each other. We can say that:
Similarly, the angle that the vector QA with the horizontal direction is
Rectangular components of a vector
As the rectangular components of a vector are perpendicular to each other, we can do math on them. This allows us to solve many real-life problems. After all, the best of physics is that it can be used to solve real world problems.
Note: Since it is difficult to use the items on the vector processor computer to your word, we, our money notation. We'll show you all the vector quantities in bold. For example, "'is a scalar quantity, and" "is a vector.
Let Ax and Ay are the rectangular components of a vector A
Then
A = Ax + Ay means that the vector A is the resultant of vectors Ax and Ay
And 'the size of the vector and Ax and Ay are the magnitudes of the vectors Ax and Ay
As we deal with rectangular components are at right angles to each other. We can say that:
A = (Ax + Ay)1/2
Similarly, the angle that the vector QA with the horizontal direction is
Q = tan-1 (Ax / Ay)
One dimensional motion
In one dimension means that the body moves in a flat and straight. As if rolling a ball on a flat table, and if we are in a straight line (not easy), then it would be one-dimensional motion.
There are four variables that have been collected in an equation to describe this motion. These are the initial velocity (u), the final velocity (v), acceleration (a), distance (s) and time (t). The equations tell us that the relationship between these variables are given below.
average speed = (u + v) / 2
There are four variables that have been collected in an equation to describe this motion. These are the initial velocity (u), the final velocity (v), acceleration (a), distance (s) and time (t). The equations tell us that the relationship between these variables are given below.
v = u + at
V2 = u2 + 2as
s = ut + 1 / 2 at2
average speed = (u + v) / 2
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