29 terms

# Physics Unit 1 :)

#### Terms in this set (...)

average speed
the total distance traveled by the object divided by the elapsed time to cover that distance
sentence: The ???, as evident from the name itself, is the ? of the ? of a moving object for the overall distance it has covered.
power
the rate of doing work, the amount of energy transferred per unit time
sentence: The standard metric unit of ??? is the Watt.
momentum
the quantity of motion that an object has
sentence: If an object is in motion (on the move) then it has ??.
centripetal force
a force that acts on a body moving in a circular path and is directed toward the center around which the body is moving
sentence: Some people confuse centrifugal force with its counterpart, centripetal force, because they are so closely related.
displacement (vector)
a ??, pointing from the start point to the end point of the path traveled.
sentence: ?? is a ?? quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
scalar
Physical quantities such as mass, volume, density, and time, are examples of ? quantities.
sentence: They can be completely described by magnitude alone.
energy
the capacity for doing work
sentence: It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms.
uniform circular motion
a movement of an object along the circumference of a circle or rotation along a circular path
sentence: A car moves along a circular road at a constant speed. Although the speed does not change, velocity is constantly changing due to the changing direction. The direction is always tangential to the circular path.
speed
how fast an object or person is moving
sentence: A fast runner has a greater ?? than a slower one.
work
a product of the force applied to the box and the distance the box is moved in the direction of the force
sentence: The unit of ? is the Newton-meter (N.m) or joule (J).
free body diagram
a symbolic representation of the forces acting on an object
sentence: These forces are vectors, represented by arrows.
acceleration due to gravity
the acceleration of a falling body in the earth's gravitational field, inversely proportional to the square of the distance from the body to the center of the earth, and varying somewhat with latitude
sentence: When a ball thrown up in the air falls back down to the ground, it speeds up as it falls.
force
something that causes a change in the motion of an object
sentence: The most familiar unit of ? is the pound.
acceleration
a vector quantity that is defined as the rate at which an object changes its velocity
sentence: ?? takes place with any change in velocity.
velocity
a physical vector quantity; both magnitude and direction are needed to define it
sentence: If a train is travelling at a speed of 150 km/h in a north east direction, its ?? is 150 km/h NE.
vector
a quantity that has both magnitude and direction
sentence: A fastball can be measured in terms of speed and ?.
center of gravity
A point, near or within a body, through which its weight can be assumed to act when considering forces on the body and its motion under ??
sentence: This coincides with the center of mass in a uniform gravitational field.
center of mass
a position defined relative to an object or system of objects
sentence: For simple rigid objects with uniform density, the ?? is located at the centroid.
instantaneous velocity
the rate of motion of an object at a point in time
sentence: The ? of an object is the velocity at a certain instant of time.
instantaneous speed
the motion rate of object at a particular time period or moment
sentence: When the speed of an object is constantly changing, the ? is the speed of an object at a particular moment (instant) in time.
static friction
the friction that exists between a stationary object and the surface on which it's resting.
sentence: It must be overcome to start moving the object.
frame of reference
a framework that is used for the observation and mathematical description of physical phenomena and the formulation of physical laws, usually consisting of an observer, a coordinate system, and a clock or clocks assigning times at positions with respect to the coordinate system.
sentence: A coordinate system is a mathematical concept, amounting to a choice of language used to describe observations.
Newton's law of universal gravitation
states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
sentence:Every object in the universe attracts every other object with a force. This gravitational force is directly proportional to the mass of the objects and inversely proportional to the square of the distance between them.
non-inertial frame of reference
coordinate system and set of points that depend on the location and orientation of objects in space and time
sentence: The laws of motion vary according to the observer's location with respect to a ?.
inertial frame of reference
coordinate system and set of points to independently locate and orient objects in space and time
sentence: The ? is a a key concept in general relativity.
Newton's laws
the three fundamental laws Isaac Newton discovered governing the motion of objects
sentence: Newton's three laws of motion describe inertia, acceleration, and equal and opposite reactions.
equilibrium
state of balance between all parts of a system
sentence: A laptop lying on a table is said to be in equilibrium, as the net force acting on it is zero.
inertia
an object's resistance to a change in motion
sentence: ? is also defined as the tendency of objects to keep moving in a straight line at a constant velocity.
net force
the resulting force determined by combining all of the forces acting on an object
sentence: A ? is defined as the sum of all the forces acting on an object.

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