# Energy Efficiency Experiments

Experiments

Method-Experiment 1

Firstly we put a light bulb into water which was about 150ml and let a current through to the light bulb. We measured the current, voltage, start temperature, final temperature and the time taken to get a temperature change of 10°C.

Experiment 1light bulb                    Data

Energy input = 7.24 x 2.07 x 262 = 3926J

Energy Input= Current x Voltage x Time

Energy output = 0.15 x 4.187 x 10 = 6.2805J

Useful energy output= Mass x Specific heat capacity x Temperature change

Wasted energy output = 3926 - 6.2805 = 3919J

Wasted energy output= Energy input – Useful Energy output

Energy → Light energy + Heat energy

Efficiency = 6.2805 ÷ 3926 x 100 = 0.16%

Efficiency=Useful energy output ÷ Energy input

Useful energy→ light

Wasted energy→ heat

Input energy→ electricity

Output energy→ light+ heat

Electrical energy→ light+ heat

Method-Experiment 2

In this experiment we ran a current through an aluminium block and recorded the temperature change of 10°C. The procedure was the same as experiment 1 as it used an immersion heater to heat up the aluminium block and then record its mass.

Experiment 2Aluminium Block

Energy input = 9.63 x 3.78 x 328 = 11940J

Energy Input= Current x Voltage x Time

Energy output = 1.0046 x 913 x 10 = 9171.998J

Useful energy output= Mass x Specific heat capacity x Temperature change

Useful energy output = 9.0414J

Electrical energy → Heat energy Efficiency = 9171.998 ÷ 11940 x 100 = 77%

Useful energy output ÷ energy input x 100

Energy input= Electrical.

Output = heat.

Useful= heat.

Wasted= heat.

Energy→ heat.

Method –Experiment 3

In this experiment we timed how long the glider went past the light gate. We measured the mass of the glider, height of the ramp at highest end, length of the ramp, measured the length of the card and recorded the time. We repeated the experiment 5 times as the air track experiment isn’t as accurate as experiment 1 and 2 so by doing it a few times will help us come up with more accurate and reliable results.

Experiment 3Air track (repeated 5 times)

Average= 40 seconds

Energy input= gravitational potential energy.

Output= kinetic energy+ heat+ sound.

Useful= kinetic energy.

Wasted= heat+ sound.

Energy input = 0.1 x 9.81 x 0.24 = 23.544J

Energy input= Mass x Gravity x Height

Energy output = 0.5 x 0.1 x (2.22 ÷ 0.4)2 = 1.54J

Energy output= 0.5 x Mass x Velocity²=0.5 x Mass (distance ÷ Time)²

Useful energy output = 1.54J

Gravitational potential energy → Kinetic energy + Heat energy

Efficiency = 1.54 ÷ 23.544 = 1.17864424%

Efficiency= Energy output ÷ Energy input

Method-Experiment 4

In this experiment we ...