# Matter in Motion

```Motion
Which unit is used to measure distance?
centimeters
An athlete is running a 5-km race at an average
speed of 8 km/h. She has to stop to tie her
shoe. After tying her shoe, she continues
running at 8 km/h. Why would her average
speed for the entire race be less than 8 km/h?
The total time she took to complete the
race increased because she stopped.
An elevator traveled 15 floors (150
ft) at a speed of 4.5 m/s. What
determine the velocity of the
elevator?
The direction the elevator traveled.
Which of the following is a definition
of motion?
A change in position over time.
Three runners compete in a 400-m
race on an oval-shaped running track.
At a certain time, one runner is 15 m
behind the finish line. Which term
describes the finish line?
reference point
Montez read that bobcats can reach
speeds of up to 30 mi/h. What does
the speed of a bobcat indicate?
The distance it can travel in a certain
amount of time .
Tyrone wants to determine how fast a bowling
ball travels when it is bowled. He uses a
stopwatch to record, in seconds, the time it
takes for the bowling ball to reach the pins.
Which unit would be most appropriate to
measure the length of the bowling lane?
meters
What would be best measured in
kilometers?
The distance a plane travels during flight
What is acceleration?
The rate at which velocity changes
An airplane leaves New York to fly to
Los Angeles. It travels 3,850 km in
5.5 hours. What is the average speed
of the airplane?
700 km/h
Which is an example of acceleration?
A bus moves on a straight road and then
makes a right turn.
Which is an example of centripetal
acceleration?
An object moving in a circle at20 m/s.
Which of the following describes an
object moving in a circle steadily?
Change in direction only.
Which scenario does not describe an
example of acceleration?
A car maintains a constant speed
Julia is in a car with her father. The
car is undergoing centripetal
acceleration. What is happening to
the car?
The car is changing direction at a
constant speed.
In order for a space shuttle to leave Earth, it
must produce a great amount of thrust. Its
rocket boosters create this thrusting force by
burning great amounts of fuel. However, once in
space, the shuttle needs very little fuel. It
circles Earth while gravity pulls it toward Earth.
What term describes the motion of the shuttle
around Earth?
orbit
High and low tides are the regular pattern of
rising and sinking ocean-water levels. They are
formed as a result of the gravitational forces
of the moon and sun on Earth’s oceans. The
moon has a greater effect on Earth’s oceans
than the sun. Why would the moon have a
greater effect than the sun?
The moon is closer to Earth than the sun
is.
What is gravity?
The force that pulls all objects toward
one another.
Two objects have a certain
gravitational force between them.
What would happen if the mass of
one of the objects suddenly
increased?
The gravitational force between the two
objects would increase.
Melanie watched the path a baseball
followed after a pitcher threw it. She
noticed that the ball traveled horizontally
away from the pitcher, as well as
downward toward the ground. What force
caused the ball to accelerate in the
downward direction when it was thrown?
gravitational force
A skydiver jumps out of a plane. She
falls downward at a very fast speed.
When she opens her parachute, she
slows down. What force pulled the
skydiver to the ground?
gravity
Which of the following would exert
the greatest gravitational force on a
body?
A planet
```