### Author Topic: Shooting the poor monkey!  (Read 17425 times)

#### Fu-Kwun Hwang

• Hero Member
• Posts: 3062
##### Shooting the poor monkey!
« on: September 02, 2009, 12:34:35 pm »
You can drag monkey or bullet with mouse, however the monkey is always been aimed as target.
Click right triangle to start the simulation.
The black line shows the relative position between bullet and the monley.
You will find the relative direction is always the same (with closer distance) because both of them are under the same gravity.

The bullet is aiming at the monkey.
If there is no gravity: the monkey will be shot.
With gravity: the monkey and the bullet will be influenced under the same gravity.
So they will fall the same dustance during the same time interval.
As loog as bullet is fired at the same time when monkey stars flaiing, the monkey will be shot.
The poor monkey is not saved by gravity.

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

#### lookang

• Hero Member
• Posts: 1772
• http://weelookang.blogspot.com
##### Re: Shooting the poor monkey!
« Reply #1 on: September 02, 2009, 01:28:59 pm »
That's a good applet on the top post

May i suggest some refinements.
idea from 1
http://webphysics.davidson.edu/physlet_resources/gustavus_physlets/monkeyandhunter.html
Likes: can allow for exploring different angles
air resistance variable for more realistic simulation?
step back < button
Dislikes: need a auto scale button for those angles and velocity where collision is outside current frame

idea from 2
http://jersey.uoregon.edu/vlab/newCannon/NewCannon_plugin.html
Likes: the slider with editable fields for duo inputs, can Ejs do this easily? i did raise a feature request on Paco's wiki http://www.um.es/fem/EjsWiki/FeedbackEn/00034 but no news yet.
field to change acceleration in the y direction, this is important for inquiry learning
the vector checkbox for velocity visualization
graph of vx vy of both ball and monkey to allow of comparison of the significance of vy ball and vy monkey
on a graph paper grid to allow for calculation of the angle instead of trial and error.

idea 3 no links because it is a commercial tool ( you can find by googling "shoot monkey" )
Likes: basketballer(instead of monkey) hanging on a tree, release hand from tree and fall, catch the ball, the morale story is sport related instead of shooting a monkey which is more suitable for promoting animal loving society that this resource can help. but a toy monkey should be fine.

idea 4

Likes: laser pointer to illustrate the straight line path instead of a line drawn, more realistic if can show how it is achieve in real life
« Last Edit: September 02, 2009, 02:06:05 pm by lookang »

#### Fu-Kwun Hwang

• Hero Member
• Posts: 3062
##### Re: Shooting the poor monkey!
« Reply #2 on: September 02, 2009, 10:32:35 pm »
The simulation was developed due to request from a teacher in Taiwan.
It was designed to show why the bullet will hit the monkey when the bullet is aiming at the monley directly.
No matter where is the monkey or the gun. (So user can drag monkey or gun with mouse).
The line connected between bullet and the monkey shows that their relative direction is always the same:
Bullet and monkey fall at the same rate (the same vertical distance during the same time interval).

Quote
the slider with editable fields for duo inputs, can Ejs do this easily?
You will find sliderset next to PlottingFrame. Add it to GUI element tree. All three elements (label,numberfield and slider will be added together).

#### lookang

• Hero Member
• Posts: 1772
• http://weelookang.blogspot.com
##### Re: Shooting the poor monkey!
« Reply #3 on: September 22, 2009, 02:19:38 pm »
oic. just saw this post
thanks!
will try it asap