Wednesday-Thursday Physics11-14-15

Questions on Projectile project

Test and Review Sheet

More general 2 dimensional motion

Project Write up is due Tomorrow, 11-15

Typed (neat)

Complete

Show all work

There will be a test on Projectile Motion

Next Tuesday (11/20)All 3 types of projectile problems

Overall velocity valuesTrigonometry

Maximum height prolems

Homework handoutpre-review problems

Answers to homework will be up on net by Friday

2 Dimensional Motion, Forces

• Combining displacements or forces in 2 dimensions is not as straightforward as we have previously done– Not just simple addition or subtraction

• The direction for motion in 2 dimensions cannot be described by a simple plus or minus

The description for force and motion values get more

complicated (longer)

Description

Boy is walking 25 meters in the North East Direction

Displacement value is =

25m [NE] or 25m (45°)

2D values

• Always written in the formMagnitude, direction

• Several ways to write the direction

[ ] use some combination of North, South, East West and the angle of direction

A single angle measured from the horizontal axis pointing right (Polar coordinates)

Direction using N,S,W,and E

• Use brackets

• First letter is the cardinal direction line used as the start of the measurement of the angle

• Number the value of the angle measured

• Last letter is the cardinal direction towards which you measure (never on the same dimension)

Coming up with the direction

Started with the south direction

Moving towards the east direction

34°

[S 34 E]

Polar Coordinates

• Angle is from 0 to 360 degrees

• 0 and 360° point due east (to the right)

• Measured going counterclockwise

Problems

Angle Descriptors:

[W 75 S]

[ S 15 W]

(255°)60°

75°Angle descriptors:

[W 60 N]

[N 30 E]

(120°)

Problem

• Describe the direction of the following vector.

13°

Answer

• [ E 13 S]

• [S 77 E]

• (347°)

Homework

• Draw a picture for each vector shown:

1) 25 m [N 37 W]

2) 14.3 m/s (197°)

3) 7.45 N [ SE ]

4) 890 m/s2 ( 342°)

5) 76.5 N [ E 49.7 S]

6) 9.34 m [ S 6.0 W ]

• Write the direction value for each vector shown:

9.6°7)

27°

8)

19 N

57.5 m

65°

9)

48 m/s