# Mechanics: 1-Dimensional Kinematics

## 1-D Kinematics: Audio Guided Solutions

#### Problem 11:

Mr. H is preparing to show the class a Strobe demonstration when he realizes that his absent-mindedness has struck once more. He left the strobe on the counter in the back of the lab after the last class period. Starting 1.0 meter from the front of the room, Mr. H walks quickly to the back of the lab, picks up the strobe and returns to the middle of the classroom. The position-time graph below represents his motion. Use the graph to answer the next several questions.

a. What is the total distance walked by Mr. H during these 8.0 seconds?
b. What is the average speed of Mr. H during these 8.0 seconds?
c. What is the average velocity of Mr. H during these 8.0 seconds?
d. How fast did Mr. H walk during the first 5.0 seconds?
e. How fast did Mr. H walk during the last 3.0 seconds?

## Audio Guided Solution

Click to show or hide the answer!

## Habits of an Effective Problem Solver

• Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
• Identify the known and unknown quantities in an organized manner. Equate given values to the symbols used to represent the corresponding quantity - e.g., vo = 0 m/s; a = 4.2 m/s/s; vf = 22.9 m/s; d = ???.
• Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
• Identify the appropriate formula(s) to use.
• Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.