Motion
true or false: All motion is relative? Explain your answer.
true or false: Newton's first law is often called the law of conservation.
False--It's known as the law of inertia.
This is a force that exists between particles. This force is attractive like gravitational force, but can also be a repulsive force.
What is electromagnetic force?
true or false: light and heat can travel through space, but sound cannot.
What is true? Sound requires a medium in which to travel. There are no gases in spaces, so sound waves have nothing to bump into or bounce off of. This is why an explosion in space would be silent.
This is the type of force that makes electricity flow in an electrical circuit. It is also the force that holds electrons in an atom, and it makes lightning.
What is electromagnetic force?
The units for speed are ______. Give an example of a unit for speed.
what is distance over time.
example: miles per hour or kilometers per second
Inertia is basically a resistance to change. A moving object will continue in motion, wanting to resist a change in that motion. A stationary object will remain at rest until a force acts upon it.
Electric circuits require a power source and a load. Give an example of a load.
What is a light bulb, computer, air conditioner, etc.
Give an example of a transparent material, a translucent material, and an opaque material.
transparent=most or all light can pass through. ex: window/glass
translucent=allow some light to pass through. ex: lampshade
opaque=don't allow any light to pass through. ex: brick wall, a human
true or false: the inclined plane and the wedge look exactly the same, but are used differently.
What is true?
Give an example of deceleration.
true
ex. pedaling a bicycle and pushing the brakes
Explain Newton's second law of motion AND give the formula.
The second law has to do with how much force is needed to affect objects. When an object is acted upon by one or more outside forces, the total force is equal to the mass of the object times the resulting acceleration.
F=mxa
Electricity is the motion of electrons from one place to another. Do electrons move from a place of lower electric energy to higher electric energy or vice versa?
What is higher to lower?
What can we say about the frequency and pitch of longer wavelengths of sound?
They have lower frequencies and lower pitch.
All simple machines create a mechanical advantage. Explain mechanical advantage.
Give a unit that represents velocity.
examples: 20 feet per second north
20 miles per hour west
What is Newton's 1st law of motion? And give an example.
An object in motion (or at rest) will tend to stay in motion (or at rest) until it is acted upon by an outside force.
ex: a stationary soccer ball or a car moving at a constant velocity.
Explain what it means for magnetic domains to be aligned.
The tiny domains have their north pole ends pointed in the same direction and their south pole ends pointed the opposite direction.
They are small amounts of electromagnetic energy. They are NOT made up of atoms, so they are not matter. But photons do sometimes behave like particles and waves.
Explain reflection and refraction of light.
Light can also bend and this is refraction.
When a car is slowing down, what happens to its speed and velocity? Is its acceleration positive or negative?
When a car slows down, its speed and velocity both decrease. The car's acceleration would be in a negative direction.
Explain Newton's third law of motion And give an example.
For every action, there is an equal and opposite reaction.
ex: A cannon moving backward when it shoots a cannon ball forward.
Electrons can spin in the same direction or in opposite directions to each other. What happens if they spin in opposite directions to each other?
They would not be aligned, and their magnetic fields cancel each other out. Substances that have electrons spinning in opposite directions, such as plastics, have a weak response to magnets. Most substances have electrons that are not aligned.
How do we perceive color? Use red as an example.
White light, which is made up of all the colors of the visible spectrum, shines on a red object. The red pigment of the object absorbs all colors of light except for the red wavelengths that bounce off the object and enter your eye. Colors we see are a result of reflected light.
White objects don't absorb any colors, so you see all the colors of the rainbow reflected back at you. Black objects absorb all the colors and don't reflect any.
If your back is to the sun and you are looking to the sky at the right angle, you can see a rainbow. It forms because each droplet of water acts like a tiny prism to bend, disperse, and reflect light back to your eye.