Category: Physics

Hall effect and applications

Hall effect and applications

Hall effect and applications                   04/29/30

 

Have you ever wondered what would happen if a magnetic field interacted with a conductive plate? If so, then you have just independently postulated the hall effect. Suppose we have a current going through a conductive plate. As one know, there is a net movement of electrons within the material. Also known is that a magnetic field will cause a deflection of charge, it’s direction depending on it’s charge. So wouldn’t it be logical that if a magnetic field were to come in contact with the plate which contains a net movement of charge, That the charges would become polarized to each side of the plate? And as a second order effect, the new disposition of charges would cause a voltage to be created?

 

One very important application of the hall effect to the field of Mechanical Engineering is known at the Wheel speed sensor. If we put such a device parallel to a rotating wheel, then the rotation of the  gears of the wheel would induce a magnetic field. If one is able to measure the changing magnetic field, then it would only be logical that we would be able to obtain a measurement for the RPM

Quantum tunneling

Quantum tunneling

   Quantum tunneling        04/29/16

 

One of the most interesting effects in the universe is known as Quantum tunneling. In Quantum mechanics, it is possible for a particle to pass through a barrier without having enough internal classical energy! To illustrate, let’s use a ball being rolled up a hill an analogy. Under classical mechanics, a ball (particle) can only roll up a hill if it has enough energy to surmount it (break the barrier. In quantum conditions however, there is a certain percentage that the ball can absorb energy from it’s surroundings to finish the job! What is extremely extremely fascinating is that water has been shown to exhibit this effect! Imagine the possible consequences, such as water being able to pour through a substance without needing to cross classical barriers.

Hydrostatics

Hydrostatics

Hydrostatics                  04/25/16

 

Hydrostatics is the study of the physics and applications of incompressible fluids at rest in stable equilibrium. The weight of a fluid displaced in water can be expressed symbolically as F=*V*g, where is the fluid density (assumed to be constant) Vis the volume, and g is gravity of the planet. The pressure on a liquid submerged in a fluid can be calculated at P= gh+P0, where Pis the pressure his the vertical displacement and P0is the atmospheric pressure (or the pressure at the top of the fluid surface). The study of hydrostatics is of fundamental importance to the field of Mechanical Engineering

Environmental stress cracking

Environmental stress cracking

   Environmental stress cracking                 04/24/16

 

One of the most common unexpected brittle failures of all thermoplastic materials is environmental stress cracking. ESC occurs when polymers are exposed to liquid chemicals that accelerate the crazing process, which results in cracking at pressures below standard air temperature. The study of ESC has application within the automobile industry, where the need to keep polymers stable is paramount

Brittleness

Brittleness

Brittleness          04/23/16

 

An object is considered brittle if it breaks from stress without significant deformation. Such an object requires little energy to be broken. The brittle strength of an object can be increased by subjecting it to pressure.

Thermoplastics

Thermoplastics

Thermoplastics         

        04/22/16

 

Thermoplastics are plastic materials that become pliable once a certain temperature threshold has been reached and revert back to being rigid once cooled to a certain temperature. The amorphous nature of thermoplastics are less susceptible to chemical attacks and environmental stress cracking due to lacking such a clearly defined structure. Teflon is an example of an application of thermoplastics

Simple Machines

Simple Machines

Simple Machines      04/15/16

 

Simple machines are devices that change the direction or magnitude of force. In summation, they can be generalized as objects that utilize Mechanical advantage to modify the force values. The six machines identified as simple machines by renaissance scientists include the Lever (a beam fixed on a pendulum or fixed fulcrum), the Wheel and axle (A wheel attached to an axle and allowed to rotate which causes a force transmission), the Inclined plane (A flat planar surface tilted at an angle which is used to lift or lower loads), the wedge (A triangular shaped portable inclined plane), and the Screw (an object that translate rotational motion into linear motion)

Mechanical advantage

Mechanical advantage

Mechanical advantage 04/14/16

 

Mechanical advantage is the measurement of force amplification achieved by using a tool. In theory, power is conserved along along an object. In a linear object like a lever being spun around in a circle the velocity of a particle existing on a point along the lever increases with distance, which can be represented symbolically by equation  (1) v=*r. The equation of power is (2) P=F*v, and since power is conserved along the object, comparing a location  Ato a location Bcan be represented as Pa=Pb→ Fa*va= Fb*vbwhich can be stated as vavb=FbFa, and by inserting equation (1) we can finally arrive at ab=FbFa, thereby proving our force amplification effect.

Thermal runway

Thermal runway

Thermal runway 04/10/16

 

Have you ever wondered if an increase in temperature could cause a further increase in temperature? This simple idea is the basis of a phenomena known as a thermal runway. In Chemical Engineering, a thermal runaway can happen if a reaction rate increases due to an increase in temperature, which causes a further increase in temperature and spins out of control. In Electrical Engineering, joule heating may diminish resistive elements which further increases current which further increases heating.

 

If one thinks about it, couldn’t this phenomena simply be modeled with differential equations?