Physics Chapter 3 Test
g = ___
-9.81 m/s²
Which change results in zero acceleration of a system? a. a change in only the direction of velocity b. a change in only the magnitude of velocity c. a change in both the magnitude and direction of velocity d. a change in only the time interval in which direction and velocity are measured
A change in only the time interval in which direction and velocity are measured
Displacement must always be measured from a. the y-axis. c. infinity. b. a reference point. d. the current position of an object.
A reference point
If an object's change in velocity is constant, then its _____ is constant.
Acceleration
The equations of motion apply only if a. acceleration is constant c. motion is horizontal b. displacement is constant d. velocity is constant
Acceleration is constant
Which one of the choices does not give you displacement, velocity, or acceleration? a. area under a velocity-time graph b. area under a position-time graph c. slope of a velocity-time graph d. slope of a position-time graph
Area under a position-time graph
|Δx| / Δt is defined as
Average Speed
On a position-time graph, the average velocity between two points is a. computed by change in position divided by change in time between the two positions. b. computed by change in time divided by change in position between the two positions. c. the horizontal displacement on the graph between the two positions. d. the vertical displacement on the graph between the two positions.
Computed by change in position divided by change in time between the two positions.
How to find displacement on a position/time graph
D2 - D1
If an object travels in a straight line, the magnitude of its displacement will be equal to the _____ traveled.
Distance
The study of the causes of motion is called
Dynamics
The speedometer on your car measures a. average speed. c. instantaneous speed. b. average velocity. d. instantaneous velocity.
Instantaneous speed
Which statement below is not a benefit of developing and using scramjets? a. It is theoretically more efficient than a ramjet. b. It is mechanically more complex (has more parts) than a ramjet. c. It can launch small space payloads and power high-flying aircraft. d. It has many military applications.
It is mechanically more complex (has more parts) than a ramjet.
The study of how objects move is called
Kinematics
Which is a possible unit for acceleration? a. ft^2 /s^2 b. m^2 /s c. m/s d. ft/s^2
ft/s^2
What replaces average acceleration in the equations of motion for a free fall?
g
Third Equation of Motion
d = (V2² - V1²) / 2a
Second Equation of Motion
d = V1*t + ½a*t²
Average velocity formula
d/Δt
A decrease of negative velocity is a(n) _____ acceleration.
Positive
Which of the following is not one of the three standard equations of linear motion?
REMEMBER C
Two-dimensional acceleration is the a. slope of a position-time graph. b. slope of a velocity-time graph. c. the area underneath a position-time graph. d. the area underneath a velocity-time graph.
Slope of a velocity-time graph.
Which of the following is a scalar quantity? a. displacement c. force b. velocity d. speed
Speed
Which of the following is not a vector quantity? a. acceleration b. displacement c. force d. speed e. velocity
Speed
The equations of linear motion apply only if a. the total motion of a system is in one dimension within its reference frame. b. system acceleration is nonzero. c. system velocity is constant. d. system acceleration is constant.
System acceleration is constant
A line that intersects a curve at a single point without crossing the curve is called a(n)
Tangent line
The area beneath a velocity-time graph within a given time interval gives a. the system's displacement during that interval. b. the distance covered by the system during that interval. c. the system's speed during the interval. d. the system's acceleration during the interval.
The system's displacement during that interval
First Equation of Motion
V2 = V1 + a*t
Velocity is a _____ because it has both magnitude and direction.
Vector
The magnitude of the slope of a line tangent to the position-time curve gives the _____ of the system.
Velocity
The slope of a two-dimensional position-time graph gives a. displacement. c. velocity. b. distance. d. acceleration
Velocity
Assuming no air resistance, which scenario is not an example of free fall? a. the motion of a piano suspended 1 m above the ground when its lift strap breaks b. the motion of your camera after you drop it over the railing at a Grand Canyon lookout c. your motion as you slide down an inclined waterslide at an amusement park d. the motion of a skydiver after jumping from an airplane
Your motion as you slide down an inclined waterslide at an amusement park
If an object's position is constant, then its velocity is _____.
Zero
Average acceleration formula
Δv / Δt
