Static Electricity
This is a material upon which negative charges build up, but does not permit the charges to pass through.
What is an insulator?
In Coulomb's Law, electrostatic force and distance follow this.
What is the inverse-square law?
Draw a circuit diagram for two light bulbs connected in series and one battery.
This is Ohm's Law.
What is V=IR?
When evaluating a velocity-time graph, how can you tell if an object is stopped?
When the line of the graph is on the X-axis, representing when the velocity is 0 m/s.
This charge repels from a positive charge.
What is a positive charge?
Electrostatic force needs this many charges in order to exist.
What is two charges?
These three conditions are necessary to light a bulb in a circuit with one light bulb, one battery, and some wire.
1) A wire connects the base of the bulb to one side of the battery
2) A wire connects the side of the bulb to the OTHER side of the battery
3) The filament within the bulb is not broken or missing
4) The battery has enough charge to light the bulb
What is the current in a circuit with a battery of 3 V and three resistors connected in series, each of 2 Ohms?
0.5 A
Imagine that a baseball is flying through deep space, far enough from any other planet so that there is no gravity or air resistance. What do you expect to happen to the ball’s speed over time?
The baseball will continue to move at the same speed forever.
According to the Triboelectric Series, this material tends to gain negatives more than acrylic.
What is styrofoam, rubber, or plastic?
What is 1/9?
What is current?
This is the total current of a circuit. Three resistors are connected in series: R1 has a resistance of 15 Ohms, R2 has a resistance of 20 Ohms, and R3 has a resistance of 10 Ohms. The battery's voltage is 9 V.
What is .2 A?
A 10 kg object and a 20 kg object are dropped from the same height at the same instant. If air resistance is negligible, which ball will hit the ground first? Explain what this implies about the force of gravity acting on the two objects.
If air resistance is negligible, then both objects will hit the ground at exactly the same time. This implies that their gravitational accelerations are the same – both objects increase in velocity at the same rate as they fall. This further implies that the gravitational force acting on the 20 kg object is twice as strong as the gravitational force acting on the 10 kg object, per Newton’s 2nd law.
An object is negatively charged when...
What is when the object has more negative charges than positive charges, or when it has a net negative charge?
This is one way to double the electrostatic force between two charges.
What is doubling the magnitude of one charge?
Draw a circuit diagram for a battery, two bulbs connected in series, and two other bulbs connected in parallel.
See Mejia's diagram
Explain why a short circuit heats up, according to the model of current electricity. You may refer to Ohm's Law.
Since current and resistance are inversely proportional, as resistance approaches 0, current will increase rapidly as there is nothing to slow down the movement of the electrons. As a result, the electrical energy will convert to thermal energy.
A semi-truck and trailer (36,000kg) driving East at 24 m/s and a van (3,000kg) driving West at 30 m/s collide.
a. If they stick together, what is the final velocity (speed and direction) of the two?
b. If instead the van bounces back (East) at 20 m/s, what will the final velocity of the semi-truck be?
a) 19.8 m/s
b) 23.2 m/s
Explain why John Travoltage was shocked when he touched the doorknob. Use the model of static electricity in your explanation.
As he walked on the carpet, the friction of his shoes on the carpet caused electrons to move from the wool rug to his rubber shoes. These charges then flowed upwards through his body, as human bodies are conductors, and rapidly discharged towards the metal doorknob, creating a shock.
Two charges that are 2 meters apart repel each other with a force of 2x10-5 N. If the distance between the charges is decreased to 1 meter, the force of the repulsion will be...
8x10-5 N
A battery has two bulbs connected in series and two bulbs connected in parallel. Explain why the current in the wire branching to the two bulbs connected in parallel is greater than the current in the wire branching to the two bulbs connected in series.
There is less resistance in the two bulbs connected in parallel, so the current is greater, as current and resistance are inversely proportional. However, for the bulbs connected in series, there is greater resistance, and as current and resistance are inversely proportional, so current is lesser.
Does the filament of a light bulb have greater or lesser resistance than the wires connecting the bulbs? Explain your thinking.
The resistance in the filament of a light bulb would be greater than that of the wire connecting the bulbs, as there is a greater loss of energy in the filament as it is both brighter and hotter than the wires.
Where did Ms. Mejia study abroad in college?
Madrid and Paris