Objects that fall freely near the surface of the Earth...
are uniformly accelerated by gravity
the time when we begin the event
the specific place where we begin measuring
Displacement in measured in...
units of length (such as meters or inches)
In the graph in Section 2.2 (pg 15), the displacement of the object between times t1 and t2 is given by the relationship
d=d2-d1 (we are not primarily concerned about the exact path taken by the object between these points. We assume that the magnitude of the displacement is given by the length of a straight line between d1 and d2 along the axis representing position)
Displacment is a ___quantity because
vector, because in addition to magnitude, it has direction.
The magnitude of displacement is known as
When the displacement between two points of time (t1 and t2) is positive, that means
its magnitude is measured in the positive direction
When the displacement between two points of time (t1 and t2) is negative, that means
the displacement is negative, and its magnitude is measured in the negative direction
Elapsed time can be given by the relationship
(slope) d/t (measured in units such as meters per second (m/s), or miles per hour (mph))
What does average velocity indicate?
how rapidly the position of the object (d) has changed over the time interval (t)
What type of quantity is velocity?
A vector quantity, because it has both magnitude and direction
What is the magnitude of velocity?
With velocity, we can use positive and negative signs to represent:
motion in opposite directions
the slope of a line drawn tangent to the graph at that point
The slope of the velocity-time graph is given by the relationship
What does Δv/t represent?
acceleration, measured in units like meters/seconds^2 (m/s^2)
When the slope of a velocity-time graph is straight,
the acceleration in this case is constant or uniform.
Equation to find the uniform acceleration of a velocity-time graph
Acceleration is a ____quantity because
vector, because it has both magnitude and direction.
A positive acceleration means that
the velocity of an object is becoming more positive with time
A negative acceleration means that
the velocity of the object is becoming more negative with time.
the object traveled the distance in the positive direction
How to calculate displacement:
Find the area underneath the line in a velocity-time graph. (add the difference displacements for all sections underneath the graph)