Interactive Textbook with assessment at PHSchool.com
Reviewing Content
Choose the letter that best answers the question or completes the statement.
Motion is described with respect to a
graph.
displacement.
slope.
frame of reference.
Displacement is distance combined with
direction.
speed.
velocity.
magnitude.
Displacement vectors of 3 m and 5 m in the same direction combine to make a displacement vector that is
2 m.
0 m.
8 m.
15 m.
Average speed is the total distance divided by the
average distance.
average acceleration.
total time.
slope.
The slope of a distance-time graph is equal to the
speed.
acceleration.
displacement.
motion.
Velocity is
the slope of a linear graph.
acceleration divided by displacement.
speed with direction.
the same in all reference frames.
Two or more velocities can be combined by
graphing the slope.
using vector addition.
calculating the instantaneous speed.
determining the rate.
A ball just dropped is an example of
constant speed.
instantaneous speed.
combining displacements.
free fall.
Acceleration is equal to
distance divided by time.
change in speed divided by time.
the slope of a distance-time graph.
change in speed multiplied by time.
The rate at which velocity is changing at a given instant is described by
instantaneous acceleration.
average speed.
constant speed.
vector addition.
Understanding Concepts
Why is it necessary to choose a single frame of reference when measuring motion?
For what kinds of distances would you choose to make measurements in millimeters? In kilometers?
Light from a star travels to Earth in a straight line at a constant speed of almost 300,000 km/s. What is the acceleration of the light?
If two displacement vectors add to yield a total displacement of zero, what do you know about the two displacements?
How will the total distance traveled by a car in 2 hours be affected if the average speed is doubled?
How do you know that a speedometer tells you the instantaneous speed of a car?
On a distance-time graph, what would the curve describing constant speed look like?
A spider is crawling on a wall. First it crawls 1 meter up, then 1 meter to the left, and then 1 meter down. What is its total displacement?
A jogger travels 8.0 kilometers in 1.25 hours. What is the jogger's average speed?
You see a lightning bolt in the sky. You hear a clap of thunder 3 seconds later. The sound travels at a speed of 330 m/s. How far away was the lightning? (Hint: Assume you see lightning instantly.)
If a river current is 8.0 m/s, and a boat is traveling 10.0 m/s upstream, what is the boat's speed relative to the riverbank?
If an object is moving with constant velocity, what do you know about its acceleration?
If the plotted points on a speed-time graph do not form a straight line, what do you know about the object's acceleration?
Explain a situation in which you can accelerate even though your speed doesn't change.