Unit 6 Two dimensional Motion

Unit 6 Two Dimensional Motion

Drawing of person on building dropping something

As the ball falls can we get a sense for how fast it is moving?

T	V	Dist fall
0	0	0
1	-10	5
2	-20	20
3	-30	45
4	-40	80
5

Can we make a distance time graph?  The best way would be to make a v-t graph?

If it fell for 5 seconds how far would it fall? 

You can also use the equations  

Freely accelerating a=-10m/s/s

Physicists, to confuse us more, will change the equation to  

If you want students to understand CAPM

1.       Start w/ v vs t graphs

2.       Make data tables

You can expect the assessments will look something like this then.

We then worked on Unit 6 worksheet 1 and then put it on the white boards.

With partners we watched a Video of steel ball on a computer and taped a transparency to screen and use marker to mark the different positions.  I could do this at school using the interactive white board.  It wouldn't be as active for the students though.

Ask question how do you think the spacing will be vertically and horizontally.

Afterwards—What did you notice about the spacing horizontally?  CVPM

What do you notice about the vertical?  CAPM

Drop ball and throw at the same time.

What do you think if it is thrown harder or softer.  If I throw it is more intriguing than using mechanism

What happens when you turn the gravity switch off? Going back to the dropping off the building

Skill set for worksheet 2  Making a motion map from the graph above.

Draw a right velocity and a down velocity.  Then draw a box and the diagonal is the

 

We then white boarded Unit 6 worksheet 2

 A white boarding tip:  Since everything is the same if you do a full class discussion you need to have questions ready, like,  "How would this be different if . . ." or give each group a different extension question.

How can we connect something we already know with something new.  What if we took the guy on the roof and extended it back (symmetry is your friend) So this isn’t very much different than the firing straight from the roof.

The bead activity.  Cut string 5 20 45 80

Find the angle where the first and last beads are at the same level.  Came up with about 53 degrees

A soccer player kicks a ball at 53 degrees.  Can we physics this up? 53 degrees is a 3-4-5 right triangle

T	X	Vx	Y	Vy
0	0	15	0	20
1	15	15	15	10
2	30	15	20	0
3	45	15	15	-10
4	60	15	0	-20

  Practicum

Roll ball down ramp and then figure out where to put the cup.

Now use the launcher Give each group an angle.  This falls into the category of really, really hard

There are a lot of different activities that we could use. But don’t spend too much time.

Summary

Horiz       Vert

CVPM    CAPM

I've always liked projectile motion and so I found that I liked this unit.  The bead thing was very nice and can illustrate things nicely for the students.  I wonder if it would be profitable to make a larger one with baseballs?  I have probably spent too much time on this in the past so I think I will have to be careful.  We did seem to jump into the problems with little instruction but Don mentioned that he usually goes through a sample with something falling from 80 meters with a horizontal velocity of 30 m/s which we didn't do to same time.  Not as much model building here, more model adapting to combine the CVPM and CAPM.  There are also not as many labs to write up in this unit.  There is a good variety of practicums to choose from with varying difficulty.

Implementation:  I do have one nice launcher that I can use for demonstrations and perhaps the practicum for the AP class.  I would also like to incorporate some rocket stuff more qualitatively than quantitatively.  If the students solidly understand the two 1D models then I don't think this will go too poorly.  They just have to get their mind around the idea that the vertical and horizontal can be done separately.