## Forces Objectives

We are starting the Forces unit. Here is a summary of what you are responsible for in this unit:

 # Objective Must-do Activities Videos 1 Explains the possible effects of a frictional force Forces Test Types of Forces 2 Calculates the force of gravity on an object System of Forces worksheet, Forces Test Types of Forces 3 Explains the effect of centripetal force on a body in motion Forces Test Types of Forces 4 Draw properly labeled free body diagrams that show all forces acting on an object System of Forces worksheet, Forces Test Free Body Diagrams 5 Determine the magnitude and direction of the resultant force for a system of forces System of Forces worksheet, Forces Test Free Body Diagrams, Resultant Forces 6 Determine the magnitude and direction of the balancing force for a system of forces System of Forces worksheet, Forces Test Free Body Diagrams, Resultant Forces, Equilibrium

## Uncertainty in Measurement

Please watch this video. Note that at 13:50, there is an error: (1.25 + 0.45) should have brackets around it.

When you are finished, tweet one (or more) questions about the video. Use the hashtag #LEARNuncertainty. Your questions could be:

• related to something that you don’t understand
• a question you think I might ask you
• a question that you think students would commonly have

## Free Fall Investigation

We will be doing our second hands-on lab of the year on November 2nd, when we will be investigating the motion of an object in free fall. Please take a look at the required materials below:

• ticker tape timer machine (110V or battery) – also known as an acceleration timer machine
• carbon paper
• ticker tape
• ruler
• clamp stand or vertical surface (such as the side of a cupboard – should be at least 1.5 meters off the floor)
• book
• 200g mass or object of similar mass

Let me know if you have any concerns in gathering the materials. If there is more than one student at your school, you can use the same equipment, but I want you to do the data gathering, calculations, and lab report writing individually. Here is a link to the instructions for the investivation (in Sakai).