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Lab 1: Three Part Lab

 

Part 1: Virtual Lab (Chapter 7)

Part 2: Open-Ended Lab (Chapter 7)

Part 3: Energy (Chapter 6)

 

Note: Turn this lab in when each part has been completed, not as separate parts. Clearly label the separate parts

 

 

Part 1: Virtual Lab (Chapter 7)

 

Instructions will be given in class concerning how to access the Physics Physlets

 

Go to Chapter 8, Linear Momentum (the chapter numbers do not correspond to your text, the concepts do)

 

Run the indicated problem and answer the stated questions for each.

 

Problem 8.1

 

a.    Find the momentum at the start of the animation.

b.    Is the momentum of the box constant during the first 1.5 seconds?

c.    Is the momentum of the box constant during the next three seconds? 

d.    Is momentum conserved during the first 1.5 seconds?

e.    Is momentum conserved during the next three seconds?

 

Problem 8.2

 

a.    Which object undergoes the greater change in momentum after colliding with the floor?

b.    Which object undergoes the greater change in kinetic energy after colliding with the floor?

c.    Is the force of the floor on the flower pot greater or less than the force of the floor on the basketball?

 

 

Problem 8.3

 

a.    Is kinetic energy constant for either collision?

b.    Which cart, top or bottom, undergoes the greater change in kinetic energy due to colliding with the wall?

c.    Is this the same cart that undergoes the greater change in momentum?

d.    Explain how carts can change their momentum but not their kinetic energy.

 

Problem 8.4

 

If the mass of the red cart is 0.8 kg, what is the mass of the blue cart? 

 

Problem 8.5

 

After the collision, the vehicles move at constant velocity.  What is the mass of the small car? 

 

Problem 8.8

 

a.    What is the magnitude of the momentum of the green cart after the collision?

b.    What is the magnitude of the momentum of the orange cart after the collision?

c.    What is the change in momentum of the system due to the release of the spring?

d.    What is the change in kinetic energy of the system due to the release of the spring?

 

Problem 8.9

 

Is the collision elastic or inelastic?  Note that the masses of the pucks are not necessarily the same.

 

Problem 8.13

 

Where should the purple one be placed in order for the center of gravity to be at the location of the black dot (position is given in meters)? 

 

 

 

Part 2: Open-Ended Lab (Chapter 7)

 

An open-ended lab is the one that you typically encounter in the "real world". You are trying to check an hypothesis or verify or show something and no guidelines or approaches are provided.

It is recommended by the AP Physics College Board that these types of problems be incorporated into the curriculum.

This lab, one of a number throughout the course, follows those very valid guidelines.

 

When 2 bodies collide, a small amount of energy is expended due to the deformation of the bodies. If the collision is elastic, all of the energy expended in changing the shape of the objects is recovered. In the case of a perfectly elastic collision, the kinetic energy of the total system containing all the objects remains constant.  If the objects involved in the collision are sufficiently rigid, then the amount of kinetic energy lost is very small and the collision, for all practical purposes can be considered elastic.

In a system in which there are no outside forces, then we can also use conservation of momentum to analyze the situation.

In this lab, it is assumed that the collision between a particle at rest and a particle that has some velocity occurs at a distance above the ground. The body with velocity attains that velocity after traversing a curved incline as shown below.

 

 

For all experiments, a first task is to design the experimantal arrangement and decide what data are to be collected. That is your task for this lab.

The objective of the lab is to verify that conservation of momentum and kinetic energy are conserved in this situation. In your report, you are to clearly state and discuss the experimental arrangement to include the collection of data.

 

You are given the following items that must be used.

 

ð The above arrangement

ð A scale

ð Paper

ð Pen

ð Measuring tape

 

Format of your report

 

1. Purpose

2. Data to be collected

3. Approach to collect the data (i.e., use the scales to determine the temperature, if appropriate)

4. Equations to use in analysis of the data that would be collected and how each would be used - the purpose - to calculate what value

 

Part 3: Energy (Chapter 6)

The above arrangement is placed on a table about 1 meter above the floor.

 

An identical steel ball is released from the top left on each of the 4 tracks shown.

 

The height above the ground from the end of the rails and the horizontal distance travelled by each of the 4 balls will be measured by a student and used by all groups.

 

Answer and turn in: LABEL THE PARAGRAPHS AS I HAVE LABELLED THEM BELOW

 

1.  Which do you think (intuitively) will travel the greatest distance horizontally after leaving the rail?

 

2.  What law(s) or principle(s) of physics are being demonstrated?

 

3.  Show your calculations for the following:

 

      a.  Velocity of the ball for each of the 4 tracks just after it leaves the end of the rail, assuming the rail is 1 meter above the floor.

 

      b.  Distance travelled by each of the 4 balls.

 

4.  What laws or principles of physics are being demonstrated?

 

5.  What are some possible sources of error?