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Definition
| Distance/Time + Direction |
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Definition
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Definition
rise/run
The steepness also tells you the slope. |
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Definition
Final Velocity-Initial Velocity
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Time
Units: meters/seconds squared |
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Term
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Definition
Forces are pushes or pulls.
Force= mass x acceleration
(This is also Newton's 2nd Law) |
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Definition
Weight is a measure of the force of gravity on an object.
Weight= mass x acceleration due to gravity
Units: Newtons |
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Term
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Definition
Momentum= Mass x Velocity
Units: kg x m/s
The Law of Conservation of Momentum says that the total momentum of the objects that interact does not change.
This is unless the objects are acted upon by an outside force. |
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Term
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Definition
Pressure= Force/area
Units: Pascals
There is pressure in fluids, which is the pressure of all of the molecules added together. |
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Term
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Definition
Density= Mass/volume
An object that is more dense that the fluid in which it's immersed sinks, and an object that is less dense than the fluid in which it's immersed floats. |
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Term
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Definition
Work= Force x Distance
Units: Joules
In order for you to do work on an object, the object must move some distance as a result of your force, and the force you exert must be in the same direction as the object's motion. |
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Term
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Definition
Mechanical Advantage=
Output Force/Input Force |
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Term
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Definition
Kinetic Energy=
mass x velocity squared/2
Units:Joules
Kinetic energy is the energy of a moving object. |
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Term
| Gravitational Potential Energy |
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Definition
Weight x height
The gravitational potential energy an object has is equal to the work done to lift it. |
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Definition
Power= Work/time
Units: Watts
A kilowatt is 1000 watts. |
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Term
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Definition
| An object is in motion when its distance from another object is changing. A reference point is an object used for comparison to see if something is in motion. |
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Term
| plates and the Theory of Plate Tectonics |
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Definition
| The upper layer of Earth consists of more than a dozen pieces called plates. The Theory of Plate Tectonics says that Earth's plates move ever so slowly in various directions. |
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Term
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Definition
A straight line shows that the acceleration is constant. This is a linear relationship.
A curved line shows that the acceleration varies each second. This is a nonlinear relationship. |
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Term
| Unbalanced/balanced forces |
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Definition
Unbalanced forces acting on an object will change the object's motion.
Balanced forces, or equal forces acting on one object from opposite directions, will not change the object's motion. |
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Term
| Inertia/ Newton's 1st Law |
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Definition
Inertia is the tendency of an object to resist change in its motion.
Newton's first Law says that objects at rest will stay at rest, and objects in motion will stay in motion unless acted upon by an unbalanced force. |
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Term
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Definition
| Newton's Third Law says that if one object exerts a force on another object, then the second object exerts an equal and opposite force on the first object. |
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Term
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Definition
Friction is the force that one surface exerts on another when the two rub against each other.
Friction's strength depends on the types of surfaces and how hard the two rub against each other. |
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Term
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Definition
Gravity is the force that pulls objects towards each other.
The acceleration due to gravity near Earth is 9.8m/s.
An object is in free fall when the only force acting on it is gravity.
The Law of Universal Gravitation says that the force of gravity acts between all objects in the universe. |
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Term
| Satellites and Centripetal Force |
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Definition
A satellite is something that orbits another object in space.
A force that causes an object to move in a circle is a centripetal force. |
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Term
| Pressure in elevation and depth |
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Definition
Air pressure decreases as elevation increases.
Water pressure increases as depth increases. |
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Term
| Pascal's principle and hydraulics |
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Definition
Pascal's Principle: When force is applied to a confined fluid, an increase in pressure is transmitted equally to all parts of the fluid.
A hydraulic system multiplies a force by applying the force to a small surface area. The increased pressure transmits to another part of the fluid, which pushes on a larger area. |
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Term
| Archimedes' Principle and buoyant forces |
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Definition
Archimedes' Principle says that the buoyant force on an object is equal to teh weight of the fluid displaced.
The buoyant force acts upwards, so it makes objects feel lighter. |
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Term
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Definition
Bernoulli's principle says that the pressure exerted by moving fluid is less that the pressure of the surrounding fluid.
This explains the lift in an airplane. |
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Term
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Definition
A machine is a device with which you can do work in a way that is easier or more effective.
Machines make work easier by changing the amount of input force required, the distance over which you exert your force, or the direction in which you exert your force. |
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Term
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Definition
Mechanical advantage:Distance from fulcrum to input force/distance from fulcrum to output force
A lever is a rigid bar that is free to pivot on a fixed point, the fulcrum.
It increases the effect of the input force and it changes the direction of the exerted force. |
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Term
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Definition
Less input force is required to do the same work.
A wedge is a device that is thick at one end and tapers to a thin edge at the other end. |
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Term
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Definition
An inclined plane is a flat, slanted surface.
Mechanical advantage: Length/height
It allows you to exert your force over a longer distance, using less force. |
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Term
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Definition
A pulley is a grooved wheel with a rope or chain wrapped around it.
Fixed pulleys change the direction of the input force and has a I.M.A. of 1.
Moveable pulleys increase the exerted force and has a I.M.A. of 2.
Pulley systems have an I.M.A. equal to the sections of rope that support it. |
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Term
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Definition
A wheel and axle is made of two circular objects that are fastened together and rotate a common axis.
Mechanical advantage: Radius of wheel/ radius of axle |
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Term
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Definition
Screws are inclined planes wrapped around a cylinder.
The closer together the threads are, the higher the mechanical advantage. |
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Term
| Machines in the Human Body |
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Definition
Levers in the body consist of bones and muscles. Joints are the fulcrums.
Incisor teeth are wedges, as they cut through the food we eat. |
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Term
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Definition
| Potential energy is stored and held in readiness, and it has the potential to do work. |
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Term
| Different Forms of Energy |
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Definition
Mechanical energy has to do with motion or position.
Thermal energy is the total energy of the particles in something.
Chemical energy is stored in chemical bonds.
Electric energy is in electric charges.
Electromagnetic energy travels in waves, and occurs in light & others.
Nuclear energy is in the nucleus. |
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Term
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Definition
Fossil fuels are fuels that were formed millions of years ago, and they contain energy from the sun.
Some fossil fuels are coal, petroleum, and natural gases. |
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