Distance & Displacement
____ is the total length of a path an object travels.
Distance
What is the SI unit for speed?
m/s
Which part of a distance-time graph represents the speed of the object being graphed?
Slope
Velocity describes the _______ and ________ of an object.
Velocity describes the Speed and Direction of an object.
What is the SI unit of acceleration?
m/s2
Displacement measures the ________ and _______ an object travels from its starting point to end point.
Displacement measures the length and direction an object travels from its starting point to end point.
What is the equation to calculate speed?
Speed = Distance / Time
S = D/T
How is an object at rest (stopped) represented on a distance-time graph?
A flat, horizontal line
How is it possible for a person's velocity to change if they are riding a bicycle around a curve at a constant speed?
Their direction is changing as you move around the curve.
Acceleration is the rate that an object's ______ changes over _______.
Acceleration is the rate that an object's Speed changes over Time.
When will displacement be equal to 0?
If your starting point is the same as your end point
Amy rides her bike 90 m in 12 seconds, stops for 5 seconds to rest, and then rides another 120 m in 13 seconds.
What is Amy's average speed?
Average Speed = Total Distance / Total Time
(90 m + 120 m)/(12 s + 5 s + 13 s) = 210 m/30s
Average Speed = 7 m/s
Look at the graph (I will show you the graph after reading the question).
Ben drove 60 kilometers from his home to Philadelphia. He stopped at his friend’s on the way.
How long did Ben stop for?
1.5 hours
Max is walking 4 m/s to the west while on an escalator which is moving 3 m/s to the west. What is Max's resultant velocity?
4 m/s + 3 m/s = 7 m/s West
After calculating acceleration, how can you determine if an object is speeding up or slowing down?
If acceleration is positive, the object is speeding up.
If acceleration is negative, the object is slowing down.
John wants to go to the park. He travels 10 m east, then realizes he went too far and has to go back 2 m west.
What is John's distance AND displacement
Distance = 12 m
Displacement = 8 m East
A train is moving 66 km/h down its track. If the train ride is 2.5 hours long, how far will the train travel?
Distance = Speed x Time
= 66 km/h x 2.5 h = 165 km
Look at the graph (I will show you the graph after reading the question).
Ben drove 60 kilometers from his home to Philadelphia. He stopped at his friend’s on the way.
Was been traveling at a faster speed during the 1st part of his trip (before he stopped) or during the 2nd part of his trip (after he stopped)?
1st part of the trip
Sarah is on a sailboat. The wind is blowing 5 m/s North. The ocean current is moving to the South 9 m/s. What is Sarah's resultant velocity?
9 m/s - 5 m/s = 4 m/s South
What is the equation to calculate acceleration?
a = (Vf - Vi) / T
Wendy is riding her bike around town. She travels 5 km south to the store, then another 12 m east.
What is Wendy's distance and displacement?
distance = 17 m
displacement = 13 m SE
How long will it take a hot wheels car rolling 1.5 m/s to travel 9 meters?
Time = Distance / Speed
= 9 m / 1.5 m/s
Time = 6 s
Look at the graph (I will show you the graph after reading the question).
Ben drove 60 kilometers from his home to Philadelphia. He stopped at his friend’s on the way.
What was Ben's average speed for the trip?
15 km/h
John throws a baseball to the north at a speed of 8 m/s. At the same time there is a cross-wind moving west with a speed of 6 m/s.
Find the resultant velocity of the baseball.
82 + 62 = c2
64 + 36 = c2
100 = c2
sqrt(100) = 10 m/s NW
Ben is driving on the highway at a speed of 25 m/s. He notices traffic ahead and reaches a speed of 18 m/s after 2 seconds. Calculated acceleration.
(18 m/s - 25 m/s) / 2 s
(-7 m/s) / 2 s
acceleration = -3.5 m/s2