Take out 2.1A Data Sheet.We will have fifteen minutes to COMPLETE the data individually.We will work together as a class to get the data tables completed.As you answer questions, I will come by and stamp HW

Bellringer: 2.1A Data Sheet

Data Table 1Description Value

Circumference (cm) 14.4

Circumference (m)circumference (cm) / 100

Total mass (gm) 750

Total mass (kg)total mass (gm) / 1000

Force (hanging mass)total mass (kg) × 9.8

Torque (wheel and axle)force (hanging mass) × radius of the wheel (m)

Data Table 2Description Value

Weight (spring scale) 0.4 N

Reading (spring scale) 2.2 N

Total force (N)weight (spring scale) + reading (spring scale)Length (lever arm) – (cm) 6.5

Length (lever arm) – (m)length (lever arm) – (cm) / 100Torquetotal force (N) × length (lever arm) – (m)

Data Table 3Description Value

Reading (spring scale) 2.2 N

Total force 2.62 N

Initial height (cm) 1.5

Final height (cm) 30.5

Distance (weight moved) (cm)final height (cm) – initial height (cm)

Conversion formula distance (weight moved) (cm) / 100

Distance (weight moved) (m)

Angle (lever arm movement)

Input torque

Input workinput torque × angle (lever arm movement)

Output worktotal force × distance (weight moved) (m)

Percent efficiency(output work / input work) × 100%

2.6

From Data Table 2

Let’s make a Foldable!!

Three half sheets of paper.

Fold as shown in the image.

Glue or staple the edges into the paper above it.

Ready to fill in!!

TITLE: WORK IN ELECTRICAL SYSTEMS

Question 1 Flap 1

What is an Electrical Field?

Answer (under top flap so it doesn’t show)

A collection of charges creates an electrical field

A force does work on an object and in an electrical system, forces are applied to charged objects by an electrical field.

Potential difference in a field results in charge moving and doing work in an electrical system.

Question 2 Flap 2

What is the formula for electrical force?What is the formula for voltage difference?

Answer (Under Flap 1) q = Charge d = DistanceE = Electrical field E = Electrical fieldFE = Electrical force DV = Voltage

differenceFE = E x q DV = E x d

Now that we know the formulas for electrical force and Voltage difference, we can use them to figure out WORK in an ELECTRICAL SYSTEM.

Question 3 Flap 3What is work in an electrical system and how do you

calculate for it?

Answer (Under Flap 2, top half)Column 1: Electrical work is the product of potential

difference and charge movedWork = Potential difference x Charge moved

**Remember that Work = Force x Distance, but electrical work is a little different ** So let’s start with what we know W = FE x d W = ( E x q) x d W = (E x d) x q W = DV x q

Units:Joules (J) = Volts (V) x Coulombs (C)

Question 3 Continued

Bottom Half Sample problem

A car battery is being charged. For 15 minutes, 800 C of charge are deposited in the battery by an average potential difference of 8V. How much electrical work is done by the charger?

GUESS

Question 4 Flap 4

What is electrical current and how do you calculate for it?

Answer (Top Half)Column 1

Current is the rate at which charge flows. Current is measured in Coulomb/sec and

represented by I. C/s = Ampere (A), which is the unit for current I = q/Dt or q = I x Dt To get electrical work, W = V x q, or W = V x I

x Dt

Units A = C/sec or C = A x sec

Question 4 continued

Bottom Half Sample problem

A 12-volt DC electric motor uses a current of 4 amperes (A). Find the electrical work done to operate this motor for 2 minutes.

GUESS

Question 5

What are the effects of electrical work and how to measure its efficiency? Electrical work produces movement,

thermal energy, light and sound in your everyday life.

But the device using the electrical work can’t use 100% of the electrical work. A motor for example gets warm; Heat is a By-product.

% Efficiency = Output work/Input work x 100%

*** Hint: Output work is usually more than input work therefore never 100% efficient (meaning energy is lost)

Now remember to glue it into your notebook on Page 66

Exit Slip: Get it Stamped!!!Now I Know

What did you learn today?? On Page 65 fill in the blanks using complete sentences/thoughts.

Now I knowThat ________________That ________________That ________________I still want to know ________________________.I am glad that I learned that__________________because__________________________________.