Newton's Laws of Motion
distance=actual path traveled; displacement=shortest path from starting point to final location
How can an object traveling at constant speed still accelerate?
by changing direction
Explain the Law of Conservation of Energy
Energy cannot be created or destroyed, only transferred and/or transformed.
name 6 simple machines
inclined plane, lever, screw, pulley, wedge, wheel and axle
What is sound?
longitudinal wave that requires matter to travel
What formula is associated with Newton's 2nd Law?
a=f/m
What does negative acceleration indicate?
An object slowing down (deceleration)
Chemical: plants, fossil fuels, batteries
Nuclear: released in nulcear fission
Gravitational: height above Earth's surface
Elastic: stored when an object is pulled tight, converted when released
how much work is done if a force of 10N moves an object 5m?
w=FxD
50J (joules)
Define frequency and describe how it affects pitch.
the amounth of wavelengths measured in a period of time
higher frequency=higher pitch
How does friction impact the motion of moving objects?
It is an opposing force.
How are speed and velocity different?
speed= d/t
Velocity= speed (d/t) and direction
What is the relationship between energy and work.
energy=ability to cause change
work=when force (from energy) acts on an object making it move (in the direction of the force)
How can someone apply force, but have no work being done?
holding an object still
throwing a ball upward
What are the three ways light interacts with matter?
transmits, reflects, absorbs
Another name for newton's 1st Law of Motion
inertia
If a car travels 150km in 3 hours, what is its average speed?
50km/h
When does a cart on a rollercoaster have the MOST kinetic energy?
coming down a hill, specifically--the moment before it begins moving back up.
How does a pulley make work easier?
changes direction of the force
part of the ear that converts sound waves into nerve signals
cochlea (inner ear)
Why doesn't a force pair result in a net force of "0"?
The forces act on each other rather than on the same object.
If an object has a force of 20N and a mass of 4kg, what is its acceleration?
5m/s2
What are the differences between thermal and mechanical energy?
Thermal-sum of kinetic and potential of the particles making up an object
Mechanical-sum of kinetic and potential of a system of objects (or parts)
How does an inclined plane make work easier?
adds distance from where force is applied
Part of the eye that contains light sensitive cells to help us see color and in dim light
retina (cone and rods cells)