physics test 3 terms
Terms
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- is the act of exerting a force through a distance in the direction of the force.
- Work –
- the ability to do work because of position in a force field.
- Potential Energy –
- the ability to do work because of motion.
- Kinetic energy -
- Total energy of a system is always constant, although energy changes from one form to another may occur within the system.
- Conservation of Energy –
- The total momentum before impact is equal to the total momentum after impact. [ pi1 + pi2 = pf1 + pf2 ]
- Conservation of momentum
- The rate at which work is done or energy is used.
- Power –
- USCS unit used for measuring mechanical power.
- Horsepower –
- The SI unit for measuring power.
- Watt –
- change in momentum.
- Impulse ( F∆t)
- The quantity of motion.
- Momentum (p)
- an acceleration towards the center of a circular path.
- Centripetal Acceleration
- is the inward force necessary to maintain uniform circular motion.
- Centripetal Force –
- ∆X / time
- Linear speed
- ∆θ /time
- Angular speed (rotational) –
- The number of complete cycles of a periodic process occurring per unit time.
- Frequency –
- The time interval between two successive occurrences of a recurrent event or phases of an event.
- Period
- a unit of measure for angular displacement. A ratio of the arc distance to the radius.
- Radian
- the amount change in angular position.
- Angular Displacement
- the time rate of change in angular speed.
- Angular Acceleration (α)
- angle required to eliminate frictional force.
- Banking Angle
- the amount of force necacary to move an object through an angular distance.
- Rotational Work
- the rate at which rotational work is done.
- Rotational Power
- any device that multiplies, divides, or changes direction of a force.
- Machine
-
Force out X
------------
Work out Force in X AMA
--------- = ------------- = ------
Work in Distance out IMA
-------------
Distance in - Efficiency
-
consist of any rigid bar pivoted at a certain point called the fulcrum.
Mi = (Fo / Fi ) = ri / ro - Lever
-
A simple machine consisting essentially of a wheel with a grooved rim in which a pulled rope or chain can run to change the direction of the pull and thereby lift a load.
Mi = (Fo / Fi ) = xi / xo - Pulley
-
A toothed wheel, that meshes with another toothed wheel to transmit motion or to change speed or direction.
Mi = No / Ni = Do / Di - Gears
-
A piece of material, such as metal or wood, thick at one edge and tapered to a thin edge at the other for insertion in a narrow crevice, used for splitting, tightening, securing, or levering.
Mi = L/t - Wedge
-
a simple machine of the inclined-plane type consisting of a spirally threaded cylindrical rod that engages with a similarly threaded hole.
Mi = si / so = 2ϬR/p - Screw
- To set at a specified downward slant.
- Pitch
-
a simple machine for elevating objects; consists of plane surface that makes an acute angle with the horizontal
Mi = (W / Fi ) = s/h - Inclined plane
-
A simple machine consisting of an axle to which a wheel is fastened so that torque applied to the wheel winds a rope or chain onto the axle, yielding a mechanical advantage equal to the ratio of the diameter of the wheel to that of the axle.
Mi = (F - Wheel and axle
- ratio of the output force to the input force.
- Actual mechanical advantage
- ratio of the distance the input force moves to the distance the output force moves.
- Ideal mechanical advantage
-
any mechanism in which power is transmitted by a continuous flexible belt
Mi = (Do / Di ) = wi / wo - Belt drive