Science s1 part 2 (38-53) NATZ VER!!!!

Why is one pump not sufficient to keep water going?

Friction slows it down

What is the cause of the weather around the globe?

Fluid always rushes from high to low pressure

What is one ampere equal to?

1 coulomb per second

What amount of current causes a painful shock?

0.001 amps

What amount of current causes a painful shock?

0.005 amps

Atoms communicate with the..

Electric force

What does EKG stand for?

Electrocardiogram

What does an EKG do?

Measure voltage across various parts of the body to measure heartbeat

Who studied “animal electricity”?

Galvani

How does modern science continue Galvani’s legacy?

By studying how different parts of the body communicate electrically

If you tub a balloon on your head, you will have generated ________ of volts of potential difference

Thousands

Which part of the battery has high potential and which part has low potential?

High=positive, low=negative

What has more volts: a balloon you rubbed on your hair or a wall outlet?

The balloon

Why is there no strong current when you rub a balloon on your hair?

The air and balloon are insulators

What is power?

The rate of energy change over time

What is one watt equal to?

One joule per second

What does a 100-watt lightbulb do?

Converts 100 joules of electrical energy to 100 joules of light energy every second

How hot can a lightbulb get?

2,000 Celsius

What was one of the early challenges of inventing the lightbulb?

Finding materials that could withstand the heat

Power is charged in…

Kilowatt hours

Electrons typically drift in wires at a speed of….

<1mm/sec

What is the speed of an electron?

Millions of meters per second

What literally is happening when you turn on a lamp switch?

It gets a signal from the power plant to turn on an electric field that accelerates the electrons

What causes an increase in temperature due to current?

The protons begin “jiggling” around

A higher temperature means a higher…

Resistance

What analogy explains why higher temperature objects have a greater resistance?

An orderly crowd vs. a rowdy crowd trying to exit a small door

What machines use superconductors?

MRIs and particle accelerators

Suppose you have a series circuit with 10V and one 8 ohm resistor and one 2 ohm resistor. How much current flows through each resistor?

Both have only 1 amp flow through

Suppose you have a parallel circuit with 12V and two resistors, one of 5 ohms and one of 10 ohms. What is the total current flowing through each?

1.2 ohms in the 10 and 2.4 in the 5

A circuit breaker is typically made of…

Metal

What devices can use over 1,000 watts?

Heaters and hair dryers

Why might an appliance become charged?

Wire becomes loose

What is the logic behind using a “grounding device”?

The ground is typically at a lower potential than a device

What was the MAIN disadvantage of Leyden jars?

They only worked once before needing to be recharged

What can effect the capacitance of a capacitor?

The size of the materials and their distance apart

What is capacitance?

How much charge a capacitor can store

At what point does a capacitor begin to push back against the current, like an “anti-battery”?

When the voltage is the same as the battery

How do dielectrics increase capacitance?

By making an opposing electric field

During a thunderstorm, turbulence causes the charges to separate to..

The top part is positive and the bottom part is negative

The storm cloud will polarize the ground, making the top of the ground…

Positive

Why is it dangerous to be near tall objects during a thunderstorm?

The lightning that strikes the tall object may dissipate charge through the ground near you

There are _____ of lightning strikes on Earth every second

Hundreds

How does Earth itself become one big capacitor?

Lightning strikes create an electric field between the atmosphere and the Earth’s surface

Why are TLEs rarely seen above clouds?

The air is too thin

Why does Venus have more frequent lightning?

It’s atmosphere is thicker and denser