## Sunday, July 19, 2015

Bungee Jumping Simulation Lab 2

Same situation as before, this time answer all the questions using energy equations, not forces.

In order to understand the physics we will start by analyzing the GIF below.  The Chrome Extension GIF Scrubber is necessary to answer the questions below.  A timing and measuring device can also be used.  You can assume that air resistance is negligible.

Question 1:  How far down are you when you feel the rope pulling?
Question 2:  At what point do you start to decelerate?
Question 3:  What would k for the cord have to be for you?

Question 4:  Using the K calculated above, what would the length of the cord have to be for you to touch the river?
Bungee Jumping Simulation Lab

Some people jump off of high points attached to a giant rubber band.  Apparently they think this is fun.  While I don’t think I will ever try, there is some great physics we can analyze.

If you are not familiar with Bungee Jumping, see Wikipedia:

https://en.wikipedia.org/wiki/Bungee_jumping

In order to understand the physics we will start by analyzing the GIF below.  The Chrome Extension GIF Scrubber is necessary to answer the questions below.  A timing and measuring device can also be used.  You can assume that air resistance is negligible.

Question 1:  How far down are you when you feel the rope pulling?
Question 2:  At what point do you start to decelerate?
Question 3:  What would k for the cord have to be for you?

Now, search for videos of Bungee jumping in New Zealand.  The link below is more visually appealing and shows more than simple bungee jumping.

The company AJ Hackett operates the Kawarau Bridge Bungee in Queensland, New Zealand.  The bridge is 43 m above the river and you can choose to stay dry, touch the river or be fully dunked.

Question 4:  Using the K calculated above, what would the length of the cord have to be for you to touch the river?
Two Dimensional Collision Simulation

The game of pool is a great example of the application of momentum and collisions.  Aiming your cue ball can create a five different types of collisions:

• ·         the cue ball moves backward
• ·         the cue ball moves forward
• ·         the cue ball stops,
• ·         the target ball moves right
• ·         the target ball moves left

In the video below, the speaker calls it “English.”

The Gif simulation below shows left English.

Use Gif Scrubber to answer to analyze the collision and answer the following questions:

1.    What is the post collision angle between the cue ball (red) and the target ball (blue)?
2.    What is the final velocity of the cue ball?

3.    What is the final velocity of the target ball?
Rotational Motion Measurement

The GIF below shows an object experiencing horizontal rotational motion similar to the spinning stopper lab.  However, in this case the sting breaks and the stopper goes flying (top of the map frame).

Using the GIF Scrubber, answer the following questions:

Before release:

1.    What is the angular velocity of the stopper?
2.    What is the linear velocity of the stopper?
3.    What is the tangential (linear) acceleration of the stopper?
4.    What is the centripetal acceleration of the stopper?
5.    What is the total linear acceleration of the stopper?

Using your height and arm extension:

6.    How long will take the stopper to reach the ground?

7.    How far horizontally from the point of release will the stopper fall?
Relative Motion Simulation Lab

Navigating a river crossing is a good example of the need to understanding relative motion.  Currents effect other modes of transportation as well.  Follow the link below to see an instructional video on how to stand up paddle board across a river.

Task:  Determine vBW from the Relative Motion Gif.

Method:
·         Use relative motion relationship vBL = vBW + vWL and information collected from the Relative Motion Gif.
·         Use the Gif Scrubber to collect your data.
·         You must develop your own experimental design and analysis methods.

Lab Report:

·         Brief explanation of method
·         Assumptions
·         Data
·         Analysis
·         Conclusion

·         Sources of Uncertainty
Graphing Accelerated Motion

The GIF below shows the progress of a car as it approaches a stop sign.  For each of the questions below please provide evidence.

1.    For what time period is the car’s acceleration increasing?
2.    What is the value of the acceleration?
3.    For what time period is the car traveling at constant velocity?
4.    What is this velocity?
5.    For what time period is the car’s acceleration negative?
6.    What is this acceleration?

## Wednesday, July 8, 2015

Rollercoaster Loop

Engineering Analysis:

The arrows on the first picture below below show the forces.  Please note that friction is not included.

Color code:  Brown is the force of gravity
Blue is the normal force going into the loop
Red is the normal force within the loop
Green is the normal force leaving the loop

Dots occur every 0.10 of a second.

This model is set up so that the car has the minimum speed to make it through the top of the loop, hence the only arrow at the top is the force of gravity.

All of the energy necessary comes from the PE at the top of the hill.  Using the image above or the GIF below, determine the minimum ratio between the hill height and radius of the loop necessary for completion of the loop.  Be sure to include the force of friction for your roller coaster material.

Safety Analysis:

A human being can only safely handle 5 g’s of acceleration without passing out.  Using the model above, ensure that your passengers will safely make in through the loop without loosing consciousness.