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