Physics Lab C Div.

New York State Coaches Clinic

October 10-11th

Poughkeepsie New York

Energy

• Work

• Kinetic Energy

• Gravitational Potential Energy

• Spring Potential Energy

• Power

• Electric Energy Stored in Capacitors

• Electrical Power

Energy Continued

• Heat Produced in Electrical Resistance

• Work done by Fluids

• Fluid Power

• Rotational Work

• Energy

• Power

Work• Work is Scalar Quantity• When a force acts to move an object, we say that Work was

done on the object by the Force. • Force is the agent of change, and Work is a measure of the change.

• The Force does the Work, not the agent that created the Force. Do not confuse the work you do to create a force with the work done by the force you create; they are not the same. The force you exert holding a 100 pound barbell above your head does no work on the barbell while the barbell is at rest, but you do work (on a molecular level) to create that force.

• W=F cosӨ*s F is constant force, s is displacement Ө is the angle between F and s.

• SI unit joule or erg.

Kinetic Energy

• Energy due to an object's state of linear motion.

• KE=1/2m*v2

• The unit of kinetic energy in any system is equal to the unit of work in that system.

Gravitational potential Energy

• Work needed to change an object's height relative to the Earth.

• E (gravitational)=mgy

• Mg= weight

• Y=difference in height

Spring Potential Energy

• Work needed to compress or stretch a spring.

• U=1/2kx2

• k = spring force constant

• x = distance from equilibrium 

Power

• Power adds the time factor to work.

• P=Δw/Δt

• Unit Watt

Electrical Energy

• Energy of a charged capacitor.

• W= ½ cv2

• C = Capacitance in farads

• V= volts

• W= work in joules

Electrical Power

• P=V*I

• P is expresses in watts

• V=Volts

• I= current in amps

Fluids

• Pressure

• Volume

• Flow

• Force

Rotational work and Power

• Linear quantities have analogous angular counterparts.

• Torque is the tendency of a force to rotate an object.

• The total kinetic energy of a rotating object has to include its rotational kinetic energy.

• Pure rolling motion is the superposition of pure translational and pure rotational motion.

Efficiency of conversions

• Losses due to heat, friction.

• Calculation of.

• Identification of.

Energy Conversions

• Matter and Energy can not be created or destroyed it changes from form to form.

• Conversion of mechanical to electrical

• Conversion of electrical to mechanical

• Conversion of electrical to electrical

• Conversion of gravitational to Kinetic

• And so forth

Alternative Energy

• Solar to Electrical

• Wind to Electrical

• Hydroelectric power

• Fuel Cells

• Geothermal

• Others

SI Units

• Students should learn and be familiar with them.

• See hand out Practical Guide to SI Units

Data Collection

• Students may be required to collect data.

• When collecting data students should show all work and record all values

• Event Supervisor may give partial credit for work completed with wrong data values.