Describe a general rule for predicting the motion of an object that is being pushed or pulled by unbalanced forces?

7th grade activities

Force and Motion

(with Work)

2010-2011

Outline of Topics:

1.     Describing Motion: Graphing, Speed and Velocity 

2.   Describing Motion: Changing Velocity

3.   Forces, Their Sizes and Direction

4.   Force and Mass

5.   Its a grave matter: gravity and inertia

6.   Weight and Mass

7.   All work and no play: Work and Energy

Appendices

1:  7th Grade Vocabulary Related to Force and Motion

2:  Motion Detector Directions

3:  Day 1 Graphs with Focus Question at the End

4:  Day 1 Data Collection Sheet

5:  Day 2 Student Problem Sheet

6:  Day 2 Second Set of Problems

7:  Day 2 Graphs for is the Velocity Changing

8:  Day 3 Student Tables with Questions

9:  Day 4 Frame for Science Notebook

10:  Day 5 Skateboard Prediction and Actual Sheets

11:  Day 6 Data Table

12: Day 7 Student Handout

13: Day 7 Force Arrows

14:  Day 8 Data Analysis

15:  Uncovering Student Ideas in Physical Science probes

16:  National Enquirer advertisements

17: Excerpt from Joy Hakim’s The Story of Science: Newton at the Center, pages 172-183

18:  Directions for converting You Tube videos to another media file

First topic:  Describing motion

A three-day exercise

Learning goals

Reviewed from 6th grade (day 1):

I can interpret a position versus time line graph to determine types of one-dimensional motion of an object.

I can draw a position versus time line graph given appropriate data.

I can represent changes in motion in a variety of ways, including words, motion arrows, graphs, and by acting out.

(Day 2) I can use the information in a position vs. time graph to determine the speed of an object.

New for 7th grade: I can define velocity.

(Day 3) I can distinguish between speed and velocity.

Topic Word Bank

Day 1  Focus Question:  What can be learned from different representations of motion?

Materials and Preparation:

For the class:

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.