Formula Fun
What is the formula to calculate speed?
Speed = distance/time
______________ is the distance an object moves per unit of time.
Speed
Give an example of a reference point
Dog walking next to a telephone pole. The telephone pole is the reference point
A speed-time graph shows the speed an object travels over a specific period of _________.
time
Ms. AP drove 60 miles to the florist to buy a succulent. It took 2 hours for her to reach the florist...honestly, not worth it. What was her speed during the adventure to buy the succulent?
s=d/t
60 miles/2 hours=30m/h
To calculate velocity, you use the same formula as you use for speed. What else do you need to include when calculating velocity?
Direction
_______________ ________________ is the starting point you choose to describe the location, or position of an object.
reference point
Mia walks 10 blocks, from her house, to the grocery store but realizes along the way that she forgot her wallet so she walks back to her house. What is Mia's displacement?
0, there is no distance from her starting point to her ending point if her ending point is the same as her starting point
What does a horizontal line on a speed-time graph indicate?
constant speed
Michael shot a flying saucer 15 m into the air. It took the flying saucer 3 seconds to fly that far. What is the average speed of the flying saucer?
avg. speed = total distance/total time
5 m/s = 15 m/3s
How do you calculate average speed?
Total distance divided by total time
Acceleration is the change in velocity over time. Give at least two examples of how you can accelerate
This can happen when an object speeds up, slows down, and changes direction.
Positive directions - you move forward
Negative directions - you move backwards
When the horizontal line is at zero velocity, the object is at ___________.
Rest
A swimmer can swim at a speed of 2.8 m/s for 6 minutes. What distance will she cover in that time?
d=s*t
6 minutes * 60 seconds = 360 seconds
2.8 m/s * 360 seconds = 1008 meters
Using the formula for speed (s=d/t), how would you calculate time?
Define instantaneous speed
The speed at a specific instant in time
What would a complete description of your position include? Give 2 out of 3
Distance, direction and reference point
When an object is undergoing constant acceleration, the line on the graph is straight but what direction is it going?
Diagonal line moving upwards
A bicyclist started from rest along a straight path. After 2 seconds his speed was 2m/s. After 5 seconds, his speed was 8 m/s. What was his acceleration during the time 2 seconds to 5 seconds?
initial speed = 2 m/s
final speed = 8 m/s
total time = 5 s-2s = 3s
acceleration = vf-vi/t
a=8 m/s-2m/s divided by 3 seconds
6m/s divided by 3 seconds = 2 m/s
What is the formula to calculate acceleration?
a=vf-vi/t
acceleration = final velocity - initial velocity divided by time
Explain the difference between average speed and constant speed
Average speed is the total distance traveled divided by the total time traveled. Constant speed is when you are moving the same distance each second that you are moving
Describe the location of something in the room relative to another part of the classroom
Example needs to include reference point, distance and direction
When you see a diagonal line moving downward, what does that mean?
A line sloping downwards represents an object with a constant deceleration i.e. it is slowing down.
A truck driver travels 75 km in 2 hours. He then drives a speed of 45 km/h for 3 hours. Next, he drives 175 km in 4 hours. What was his average speed?
45km/h*3 hours = 135 km
135 km + 75 km + 175km = 385 km
2 hours + 3 hours + 4 hours = 9 hours
385 km/9hrs = 42.8 km/hr