What is the difference between distance and displacement?
Distance = how far you moved in total (scalar)
Displacement = how far, and in what direction, you are from where you started (vector)
What is the difference between speed and velocity?
Speed = the rate at which an object covers distance; how fast something is moving (scalar)
Velocity = the rate at which an object changes position (displacement); speed in a direction (vector)
What is acceleration?
the rate of change of an objects velocity
What does the slope of the line tell you on a distance-time graph?
The speed of the object
(rise / run) = (change in distance / time)
What does the slope of the line tell you on a speed-time graph?
The acceleration of the object
(rise / run) = (change in speed / time)
Positive slope = increasing speed
Negative slope = decreasing speed
What formula would you use to calculate the displacement of this trip?
Pythagorean's Thereom
a2+b2=c2
How do you calculate speed?
How do you calculate velocity?
Speed = Distance / Time
Velocity = Displacement / Time
What are the 3 types of acceleration?
2. Decreasing speed (negative acceleration/ deceleration)
3. Changing direction
Describe what is happening during segment A.
The object is moving away from the origin a distance of 30 km in 2 hours, at a constant speed of 15 km/hr.
Describe what is happening during segment A.
The object is accelerating from rest to 15m/s in 10s at a constant rate of 1.5m/s2
What is the total distance and displacement of a person who runs the perimeter of this field 5 times?
Distance = 100m (20 x 5)
Displacement = 0m
What is the average speed of the car in km/h?
S = D/T
8km / 0.25 hr = 32 km/h
How do you calculate acceleration?
a = change in speed / change in time
a = (vf - vi) / t
Describe what is happening during segment B.
Slope = zero, which means the speed is zero.
The object is not moving; object is stationary for 1 hour.
Describe what is happening during segment B.
Calculate the distance and displacement of the skier.
Distance = 360 m
Displacement = +120 m or 120 m right
Calculate the average speed and velocity if the trip took 2 hours. (The red is the actual path traveled)
Speed = 5.5 km/h (11km / 2hr)
Velocity = 2.5 km/h NE (5km NE / 2hr)
What's the average acceleration after the first 3 seconds?
a = 3 m/s2
(19m/s - 10m/s) / 3s
Describe what is happening during segment D.
The object is moving back toward the origin a distance of 60 km in 1.5 hours, at a constant speed of 40 km/hr.
Describe what is happening during segment D.
The object is decelerating from 25m/s to 0m/s in 20s, at a constant rate of -1.25m/s2.
Calculate the distance and displacement (1 unit = 1 m)
Distance = 13 m
Displacement = 5 m NE (42+32=c2)
Solve all three S/D/T questions. Include proper units.
1. S = 25 m/s (100m / 4s)
2. D = 240 km (80km/h x 3hr)
3. T = 3 hr (21km / 7km/h)
Answer the 3 questions above.
1. a = 2.5m/s2 (25m/s - 15m/s) / 4s
2. a = -5m/s2 (10m/s - 20m/s) / 2s
3. a = 0 m/s2 (constant velocity = not accelertaing)
Calculate the total distance traveled as well as the average speed of the entire trip.
Total Distance = 120 m (60 away + 60 back)
Average Speed = Total Distance / Total Time
AS = 120m / 5 hr = 24 km/hr
Calculate the total distance traveled as well as the average speed of the entire trip.
Total Distance = 75+150+200+250=675m
A (15x10)/2 = 75m
B (15x10) = 150m
C (15+25)/2 x 10 = 200m
D (25x20)/2 = 250m
Average Speed = Total Distance / Total Time
AS = 675m / 50s = 13.5 m/s