OAR Mechanical Comprehension
Scalars - answer Quantities that are fully described by a magnitude alone.
Vectors - answer Quantities that are fully described by both a magnitude and a
direction.
Distance - answer Scalar quantity that refers to "how much ground an object has
covered" during its motion.
Displacement - answer Vector quantity that refers to "how far out of place an object is" it
is the object's overall change in position.
Speed - answerScalar quantity that refers to "how fast an object is moving."
Velocity - answerVector quantity that to "the rate at which an object changes its
position."
Force - answerVector Quantity that describes the force acting up an object.
Contact Forces:
Frictional, Tension, Normal, Air Resistance, Force, Applied, and Spring
Action-at-a-Distance Forces:
Gravitational, Electrical, and Magnetic
Average Speed - answerAverage Speed =
Distance Traveled/ Time of Travel
Average Velocity - answerposition/time = displacement/time
Acceleration - answerVector quantity that is defined as the rate at which an object
changes its velocity.
Ave. Acceleration - answerVelocity/Time
Mechanical Advantage - answeroutput force/input force = MA
Maximum Weight Questions - answerForce x Mechanical Advantage = MW
If the rope on the end of a pulley system with a MA of 3 is pulled with 160 pounds of
force, what is the maximum weight that can be lifted? - answer160 x 3 = 480 lbs
, Force Necessary Questions - answerWeight/MA
Mechanical Advantage of an incline plane - answerlength/height = MA
A 240-pound block is being pulled up an incline by a pulley. The incline is 20 feet long
and rises 5 feet. Neglecting friction, how much force is necessary to move the block up
the incline? - answer20/5 = 4
240/4 = 60
Bernoulli's Principle - answer- The air pressure on top of an airplane wing is less than
on the bottom of the wing. The velocity of wind on top of the wing is greater than below
the wing.
- As the velocity of a fluid or gas increases, the pressure decreases.
Inversely Proportional - answerwhen one value increases, as the other decreases.
Directly Proportional - answerWhen one value becomes larger or smaller and the other
becomes larger or smaller
larger = larger
smaller = smaller
Boyle's Law (if temperature is held constant, inversely proportional) - answerThe
absolute pressure and volume of a gas are inversely proportional, as long as the
temperature is held constant. If volume is halved, the pressure is doubled.
Volume Increases = Pressure Decreases and vice verse
Charles' Law (if pressure is held constant, directly proportional) - answerGasses expand
when heated. If the temperature on a gas is increased, the volume of the gas increases.
Volume and temperature of a gas are directly proportional at a constant pressure.
Temperature ^
Gases ^
Newtons' First Law - answerAn object at rest stays at rest and an object in motion stays
in motion with the same speed and in the same direction unless acted upon by an
unbalanced force.
Utilizes Velocity and Force both Vector quantities to calculate NET FORCE add or
subtract depending on the direction of the object.
Inertia - answerThe resistance an object has to a changes in its velocity (Newtons First
Law).
Scalars - answer Quantities that are fully described by a magnitude alone.
Vectors - answer Quantities that are fully described by both a magnitude and a
direction.
Distance - answer Scalar quantity that refers to "how much ground an object has
covered" during its motion.
Displacement - answer Vector quantity that refers to "how far out of place an object is" it
is the object's overall change in position.
Speed - answerScalar quantity that refers to "how fast an object is moving."
Velocity - answerVector quantity that to "the rate at which an object changes its
position."
Force - answerVector Quantity that describes the force acting up an object.
Contact Forces:
Frictional, Tension, Normal, Air Resistance, Force, Applied, and Spring
Action-at-a-Distance Forces:
Gravitational, Electrical, and Magnetic
Average Speed - answerAverage Speed =
Distance Traveled/ Time of Travel
Average Velocity - answerposition/time = displacement/time
Acceleration - answerVector quantity that is defined as the rate at which an object
changes its velocity.
Ave. Acceleration - answerVelocity/Time
Mechanical Advantage - answeroutput force/input force = MA
Maximum Weight Questions - answerForce x Mechanical Advantage = MW
If the rope on the end of a pulley system with a MA of 3 is pulled with 160 pounds of
force, what is the maximum weight that can be lifted? - answer160 x 3 = 480 lbs
, Force Necessary Questions - answerWeight/MA
Mechanical Advantage of an incline plane - answerlength/height = MA
A 240-pound block is being pulled up an incline by a pulley. The incline is 20 feet long
and rises 5 feet. Neglecting friction, how much force is necessary to move the block up
the incline? - answer20/5 = 4
240/4 = 60
Bernoulli's Principle - answer- The air pressure on top of an airplane wing is less than
on the bottom of the wing. The velocity of wind on top of the wing is greater than below
the wing.
- As the velocity of a fluid or gas increases, the pressure decreases.
Inversely Proportional - answerwhen one value increases, as the other decreases.
Directly Proportional - answerWhen one value becomes larger or smaller and the other
becomes larger or smaller
larger = larger
smaller = smaller
Boyle's Law (if temperature is held constant, inversely proportional) - answerThe
absolute pressure and volume of a gas are inversely proportional, as long as the
temperature is held constant. If volume is halved, the pressure is doubled.
Volume Increases = Pressure Decreases and vice verse
Charles' Law (if pressure is held constant, directly proportional) - answerGasses expand
when heated. If the temperature on a gas is increased, the volume of the gas increases.
Volume and temperature of a gas are directly proportional at a constant pressure.
Temperature ^
Gases ^
Newtons' First Law - answerAn object at rest stays at rest and an object in motion stays
in motion with the same speed and in the same direction unless acted upon by an
unbalanced force.
Utilizes Velocity and Force both Vector quantities to calculate NET FORCE add or
subtract depending on the direction of the object.
Inertia - answerThe resistance an object has to a changes in its velocity (Newtons First
Law).
