AP Physics Chapter 2 Study Guide

Kinematics: Speed and Velocity

 

Displacement: A change from one position to another position.

displacement

 

Position and Displacement

 

Average Speed:the distance traveled divided by the time it took to travel the path.

average speed

average speed

Average Velocity

 

Problem 1

You drive a beat-up pickup truck along a straight road for 8.4 km at 70 km/hr, at which point the truck runs out of gasoline and stops. Over the next 30 minutes, you walk another 2.0 km farther along the road to a gasoline station.

a) What is your overall displacement from the beginning of your drive to your arrival at the station?

 

 

b) What is the time interval Δt from the beginning of your drive to your arrival at the station?

 


c) What is your average velocity from the beginning of your drive to your arrival at the station? Find it both numerically and graphically.

 

 

 

d) Suppose that to pump the gasoline, pay for it, and walk back to the truck takes you another 45 minutes. What is your average speed from the beginning of your drive to your return to the truck with the gasoline?

 

 

 

 

Problem 2

Plot the position v. time graph for an elevator that is initially stationary, then moves upward, and then stops. Plot velocity v. time for the elevator. Plot acceleration v. time for the elevator.

elevator

 

 

 

 

Constant Speed

constant speed

Constant speed means you travel the same distance for each time interval. The equation is the same as the one you used in Algebra

d = rt.

constant velocity

 

What do you notice about the bee traveling at a constant speed?

constant velocity

 

What is the difference between these graphs?

constant velocity

 

How do you calculate the distance traveled from a velocity v. time graph?

 

constant velocity

 

Instantaneous Speed:

instant speed

 

instant speed

 

Formula for Instantaneous Speed instant speed.

 

tangent

 

tangent

 

On to Vector Practice