## Description

#1 (12). The definition, symbol, formula, what each symbol represents and units of the terms

Energy- is defined as the ability to do work. In physics it is a physical scalar quantity. The SI unit of energy is Joule and its symbol is shown as E.

Formula of calculating energy is J=N* m i.e. Joule = Newton * meters

Potential energy- this is energy that any given object has because of its position in any given force field. It is known as potential energy since it is convertible to other forms. Its symbol is U.

Its formula is U=mgh which represents mass*gravitational acceleration* height

Kinetic Energy-this is type of energy an object possesses when in motion. Its symbol is K. Kinetic energy formula K= ½mv2i.e. half *mass*velocity squared

Specific internal Energy-the specific internal energy of any material is the internal energy of that material per unit mass. Its symbol is u.

Formula is given by dividing the total energy U by the total mass m. its units are Btm/Ibm

Specific P-V Energy-This is energy generated electrically by converting solar radiation to a direct electrical current by means of semiconductors that portrays the photovoltaic properties.

Specific Enthalpy-this is a fluid property which is defined in terms of h=u+pv, where u= specific internal energy and p=absolute pressure of the system. The SI units is joule per kilograms

Work- this is the force that moves an object. It is represented by symbol W. Its SI unit is Joule. Thus work formula is W=N*m

Heat transfer per Unit Mass-this is amount of energy absorbed by a body that can be transferred from one body in one unit of mass to change any system temperature.

Sensible heat-it is the energy exchanged from one system that changes in temperature and leaves some properties of system unchanged example the volume of that system.

Latent Heat-this is amount of heat required to change a solid material to liquid or vapor.

Entropy-this is the degree of lack of order in a given mechanical system.

Heat Capacity-this is the amount of heat absorbed by a material for that material to raise in temperature by one degree

# 2(4). Difference between latent heat of fusion and latent heat of vaporization

Latent heat of fusion is the energy thereof necessary to change the phase of a solid to liquid. The energy absorbed or released in changing the state of matter from liquid to gas is latent heat of vaporization.

3 #6 Determine the potential energy of a box with a mass of 40 pounds on top of a wall 7 feet high.

Ei + W = Ef

W = Ef – Ei

= 0 – GPEi

= – mgh

= -(40kg)(9.8 m/s2)(7 m)

= – 2744 kg-m2/s2

W = -2700 J

#4(6).

F=MV

M = MASS

V = VELOCITY

M= 7 OUNCES

V = 65M MILES PER HOUR

Force = 65*7

455.

References

The splung. Difference between latent heat of fusion and latent heat of vapourisation. n.d. Web

Retrieved from http://www.splung.com/content/sid/6/page/latentheat