Describing Motion
A car goes from 80km/h to 20km/h in 0.5 h. What is the acceleration in km/h^2?
-120 km/h^2
A distance-time graph shows a horizontal line. This means that the velocity is
0 / not moving
If you are riding your bike around the block, returning to the exact point where you started, what is your displacement?
0 ft
A swimmer swims 20 m in 40 s. What is the swimmer's average speed?
0.5 m/s
Use the formula r = d/t to find the average speed of a dog that runs 10 m in 20 s.
0.5 m/s
A train traveled 250 kilometers from its starting point in 5 hours. If the train continues at the same average speed for another 4 hours, how far will it have traveled from its starting point? Show your work.
1) 250/5 = 50 (50 km/h) 2) 50 x 4 = 200 3) 200 + 250 = 450 km It will have traveled 450 from its starting point
A top-fuel dragster accelerates from rest to velocity of 100 m/s in 8 s. What is the acceleration?
12.5 m/s^2
Suppose that the average speed your dog can run is 2 m/s. Remember, average speed = total distance/total time. How much time will it take your dog to run 120 m?
60 seconds/1 minute
You travel 190 km in 2 hr. What is your speed in km/h?
95 km/h
The distance traveled divided by the time taken to travel the distance is a) average speed b) mass c) momentum d) speed
A
The total distance traveled by an object divided by the total amount of time needed to travel equals the a) average speed b) friction c) average acceleration d) net force
A
To describe velocity you need to know a) speed and direction b) speed and time c) direction and acceleration d) speed and acceleration
A
What is the term for speed at any instant in time? a) instantaneous speed b) variable speed c) constant speed d) average speed
A
When a car slows down at a traffic light, it is a) accelerating b) traveling at a constant velocity c) decreasing its displacement d) changing direction
A
Which best describes how velocity changes with time? a) acceleration b) average speed c) gravity d) inertia
A
Which of the following statements best describes the motion of the object (graph number 38 on review) a) the object moved at a constant speed b) the object accelerated at a constant rate c) the average speed of the object was greater than 1 m/s d) the instantaneous speed of the object was greater than 1 m/s
A
Which one of the graphs represents a car whose speed is increasing? ( on a speed time graph)
A straight diagonal line going up
Which one of the graphs represents a car standing still (on a distance-time graph)
A straight horizontal line
Which one of the graphs represents a car whose speed is decreasing? (on a speed-time graph)
A straight horizontal line going down
Which line travels at the fastest speed. Justify your answers (A - steepest, B- In the middle, C - lowest)
A, because it is the steepest
A starting point that can be used to locate a place or thing is a ____ point a) dimension b) reference c) position d) motion
B
Acceleration is a change in a) speed b) velocity c) displacement d) position
B
During which time interval was the object moving fastest? (graph number 37 on the review) a) 0 to 1 s b) 1 s to 2 s c) 2 s to 3 s d) 3 s to 4 s
B
Which best explains the graph below? (Speed - distance graph with a slanted line going up) a) the speed is zero and does not change b) the speed of the object increases at a steady rate over time c) the speed of the object decreases at a steady rate over time d) the speed of the object increases and decreases over a given amount of time
B
You travel 200 km in 2 hr. Your ____ speed is 100 km/h a) constant b) average c) instantaneous d) initial
B
If someone is walking on a moving bus, name two reasonable reference points you might use to describe his or her motion.
Bus door or bus seat (?)
Which of the following best describes how constant velocity is shown in a speed-time graph? a) a line curving down b) a line curving up c) a straight horizontal line d) a straight diagonal line
C
A soccer ball takes 20 s to roll 10 m. What is the average speed of the soccer ball? a) 200 m/s b) 5 m/s c) 2 m/s d) 0.5 m/s
D
Acceleration involves a change in a) time b) direction c) speed d) both b and c
D
According to the graph (on question 38 from the review), about how long did the object take to move 40 m? a) 2 s b) 3 s c) 4 s d) 5 s
D
Displacement is the difference between the initial position and the ___ position of an object a) positive b) resting c) motion d) final
D
Motion is change in a) speed b) velocity c) force d) position
D
Motion is the process of changing a) reference b) dimension c) displacement d) position
D
On a speed-time graph, a perfectly straight horizontal line shows the change in speed is a) -10 b) 10 c) 1 d) 0
D
When an object is at rest, what is its speed? a) 2 m/s b) 3 m/s c) 1 m/s d) 0 m/s
D
When you graph the motion of an object, you put ____ on the horizontal axis and ____ on the vertical axis a) speed, time b) distance, time c) direction and acceleration d) time and distance
D
When you interpret a distance-time graph, the speed of the object is determined by a) looking at the values on the x-axis b) looking at the values on the y-axis c) finding the length of the graph line d) finding the slope of the graph line
D
Describe the motion of a car with an acceleration of -2 m/s^2.
Deceleration/slowing down
A speed that does not vary is called average speed
False
Acceleration is defined as the rate of change of position
False
An object's position is defined in relation to the speed of another object
False
If a bicycle moves in a straight line, its velocity cannot change
False
The average speed of a snail can be measured with observation
False
If you are driving up a curvy mountain road, your displacement would be greater than your distance.
False - lesser
When you run a track at 5 km/h your velocity is constant
False // always changing OR accelerating
If you travel though a city and find that you travel 5 km in 30 minutes, you could say that your constant speed is 6 km/h
False // average
The speed you read on your speedometer is the constant speed.
False // instantaneuos
Motion is a change in direction
False // position
You are going 70 km/h and another car passes you going in the opposite direction at 70 km/h. Do both cars have the same velocity? Explain.
No, because the cars are going in opposite directions
____, not velocity is used to calculate the average acceleration
Speed
Which one of the graphs represents a car moving at a constant speed? (on a distance-time graph)
Straight diagonal line going up
A line on a speed-time graph with a steep slope indicates a greater speed
True
To determine if an object has changed position, you need to know its position relative to another object
True
Velocity changes when the direction of motion changes
True
When an object's speed changes, its velocity also changes
True
When you ride your bike around a corner at 10 m/s, you are accelerating
True
Speeding up, slowing down, and going around curves are examples of
acceleration
The measure of how much the velocity of an object changes in a unit of time
acceleration
A change in the velocity during a time interval divided by the time interval during which the velocity
average acceleration
The total distance traveled divided by the total time taken to travel that distance
average speed
To calculate _______ you divide distance traveled by the time it takes to travel that distance.
average speed
The rate of change of position in which the same distance is traveled each second
constant speed
The difference between the initial position and the final position of an object
displacement
A speed at a specific instant in time
instantaneous speed
The speed you read from your speedometer is your
instantaneous speed
The SI unit for speed
meters per second
The process of changing position is
motion
the process of changing position
motion
An object's distance in a certain direction from a reference point
position
A starting point that can be used to locate a place is called a
reference point
A starting point that can be used to locate a place or thing
reference point
A measure of the distance an object travels per unit of time
speed
The three ways to accelerate an object are _____, _____, or _____
speed up, slow down, change direction
The speed and the direction of a moving object
velocity
