Table that shows the mass of the balls and the depth of the crater:

This is the video analysis of the free fall movement of the ball done with Logger Pro by María Gallego and Coral Conde 10B.

05/05/2014

Free fall Session 4: CORAL CONDE

Today we have been recording some videos in order to analyse them in logger pro, we also looked at some of the videos so that we could do it correctly.

21/04/2014

Free fall session 3: CORAL

Today we have had class with Mr. Canning (as our teacher wasn't here). I continued with my experiment and I have finished it. I have changed a bit the way I was doing it although the variable is still the mass of the ball. However, now I have 5 new different balls with different masses and I did each of them 5 times. 

For next class, I will record the experiment as I didn't do that during this class. I threw the ball from a distance of 50 cms from the container and I used gel to calculate the depth of the ball.

BALLS:

Ball 1: 5 grams

Ball 2: 15 grams

Ball 3: 30 grams

Ball 4: 50 grams

Ball 5: 80 grams

RESULTS:

Mass of the ball (grams)    Depth of the ball in the gel     Average of the depth

21/04/2014

Lab experiment (by: María Gallego)

Research question:

How does height affect to the impact of an object over sodium polyacrelate?

Hypothesis:

My hypothesis is that the higher the altitude the object is dropped from, the higher the velocity it will reach, resulting in a greater impact force and a larger crater in the sodium polyacrelate compound.

Any free falling object has an acceleration of - 9.8 m/s².Therefore, as the height increases more and more, the object will have more distance to accelerate and it will reach a higher velocity.

A vector is a geometric quantity which has a magnitude and a direction. A momentum is the product of the mass and velocity of an object. It is a vector, as it has a direction and a magnitude.  (Physicsclassroom.com, 2014)

The physicist Isaac Newton developed a theory to get rough approximations of the impact depth of projectiles travelling at high velocities. I know a 5g ball of marble is not the same as a projectile, but the idea is the same.

When we let the ball fall to the ground, it has an acceleration of 9.8m/s2 due to gravity. Each second, the velocity of the ball increases. When it reaches the floor it has a momentum which is equal to its mass (2kg) times its final velocity. In order to stop the ball, this momentum must be transferred into another mass, this is the mass directly in front of the ball (sodium polyacrelate), which will be pushed depending of the ball’s velocity. The higher the velocity the further the plasticine will be pushed. The impact depth depends on the mass and the velocity of the impactor. The impactor (the ball) will stop when its momentum is transferred to the sodium polyacrelate compound, this is, when it penetrates in the sodium polyacrelate, a depth that is equal to its own length times its relative density divided by the density of the mixture. (Physics.le.ac.uk, 2014)

D= depth; A= density of the impactor (ball); B= density of the target mass (sodium polyacrelate); L= length

D= L·(A/B)

The velocity (v) of a falling body that falls from rest is found by multiplying g by the time (t) during which a body falls: v = gt

The impactor, the ball, is a vector, as it has a magnitude (its length) and a direction

With this I conclude that the height (factor) is directly proportional to the impact depth (effect), as the higher we throw the ball from, the higher velocity it will get, resulting in a higher momentum which leads to a greater impact causing a larger crater.

Variables

Independent variable: height (o.5m, 1m, 1.5m , 2m, 2.5m)

Dependent variable: depth of the crater in sodium polyacrelate

Controlled variables: mass (5g), force (the only force that will be applied at the ball will be gravity), direction (it will have a straight fall), shape (round), material of the ball (marble), material where the ball will fall (sodium polyacrelate).

Materials

Sodium Polyacrelate

5g plastic ball

Bench

Beaker

Ruler

A friend

Method:

1.       Put a 250mL beaker filled with sodium polyacrelate just where you are going to drop the ball.

2.       Climb a ladder so you are 0.5 meters above the brick of plasticine. Measure the distance with a       ruler between the brick of plasticine and the point where you are going to drop the ball from.

3.       Have a friend next to the beaker so that he/ she chronometers the time the ball takes to reach the     floor.

4.       Drop the ball (without adding any force).

6.       Get down of the ladder and measure the crater the ball has made in the compound.

7.       Measure with a ruler the crater the ball has made.

8.       Write down the results in the notebook.

9.       Repeat the same process but increasing the height (o,5m, 1m, 1.5, 2m, 2.5m)

      

       Data:

Graph: Height (from where I drop the ball)- Depth of the crater

      Table: Height (from where I drop the ball)- Depth of the crater

Height (m)	0.5					1
Height of the crater  (cm)	1	2	3	4	5	1	2	3	4	5
	1.2	1	1.2	1.4	1.4	2	2.5	2.5	2.5	2.3
Average (cm)	1.24					2.36

1.5					2					2.5
1	2	3	4	5	1	2	3	4	5	1	2	3	4	5
4.5	4.7	5	5	4.9	3.5	4.0	4.1	4.0	4.5	5.0	5.0	5.1	5.3	5.5
4.82					4. 02					5.18

Conclusion and evaluation:

The results of this experiment, which are shown at the table and the graph, support the hypothesis that the higher the altitude the object is dropped from, the larger the crater in the sodium polyacrelate compound will be. With the graph we can easily see that between the height from where the ball is dropped and the depth of the crater there is a proportional relationship, if the height increases the depth does too, and vice versa. 

However, the alignment of the dots at the graph is not perfect. This could be due to mechanical error during the procedure. The accuracy of the results could be improved using a larger recipient, as the one we used was so small that it was very difficult to hit in the sodium polyacrelate solution with the marble. The error may have also occurred due to the lack of accuracy we had during the measurements as much to the height the ball had to be dropped from as to the depth of the crater.

Finally, with this experiment I was able to answer my research question, not only by looking up the information in the internet (from where I got my information for backing up my hypothesis), but also by verifying it myself and confirming it with an experiment.

Bibliography:

Bbc.co.uk. 2014. BBC - GCSE Bitesize: Gravitational potential energy (GPE). [online] Available at: http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/forces/themeridesrev1.shtml [Accessed: 17 Feb 2014].

Diangco, M. and Profile, V. 2014. Free Fall Motion: Kinematic Equations for Free Fall. [online] Available at: http://motionfreefall.blogspot.com.es/p/kinematic-equations-for-free-fall.html [Accessed: 19 Jan 2014].

Education.com. 2014. Does Height or Distance Affect Impact? | Education.com. [online] Available at: http://www.education.com/science-fair/article/does-height-or-distance-affect-impact/ [Accessed: 21 Jan 2014].

Hyperphysics.phy-astr.gsu.edu. 2014. Energy of falling object. [online] Available at: http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html [Accessed: 19 Jan 2014].

HowStuffWorks. 2014. HowStuffWorks "Falling Bodies". [online] Available at: http://science.howstuffworks.com/falling-bodies-info.htm [Accessed: 17 Feb 2014].

Physicsclassroom.com. 2014. Kinematic Equations and Free Fall. [online] Available at: http://www.physicsclassroom.com/class/1dkin/u1l6c.cfm [Accessed: 21 Jan 2014].

Physicsclassroom.com. 2014. Vectors and Direction. [online] Available at: http://www.physicsclassroom.com/class/vectors/u3l1a.cfm [Accessed: 17 Feb 2014].

Physics.le.ac.uk. 2014. [online] Available at: https://physics.le.ac.uk/journals/index.php/pst/article/viewFile/589/403 [Accessed: 17 Feb 2014].

 S-cool.co.uk. 2014. GCSE Physics Energy Calculations Revision - Gravitational Potential Energy | S-cool, the revision website. [online] Available at: http://www.scool.co.uk/gcse/physics/energy-calculations/revise-it/gravitational-potential-energy [Accessed: 17 Feb 2014].

Logger pro 3

This is a graph made with logger pro 3. The data is obtained from this video:

31/03/2014

Free Fall Investigation Session 2: CORAL

In this lesson, we have started the experiment and I have been working on my own (as my partner is missing) starting to perform it. I have been able to take some pictures and some videos and I weight some of the balls. Here I post some of the photos. We had a change in 

BALL 1: 0,32 grams

´

BALL 2: 0,20 grams

BALL 3: 0,26 grams

Free Fall Investigation, 1st Session.

Isabel and Mnauel have been paired together and we are going to work on Manuel's experiment about how the height from which the ball is dropped affects the distance the ball manages to travel into the jelly.
We have been working on the list of materials:

• Jally powder
• Glass Marble
• Water
• Notebook
• Videocamera
• Video analysis Logger Pro.

Our hypothesis is that the higher the ball is dropped from, the more distance the marbel will travel into the jelly as it will acquire more velocity during he freefall.

24/March/2014

FREE FALL INVESTIGATION, 1st session 

Today in the lab the teacher has explained to us how we are going to work in the following sessions and the criteria evalutaed.

María and me are going to work together but each of us with her own experiment. Eventhough the marks and the work will be individual, we are going to help each other and we have some common materials (as both of us are measuring the deformation of plasticine).

Materials (common ones): 
Camera
Plasticine
Ruler
Logger Pro
Notebook

Materials (my own ones):
7 balls of different materials, and therefore different mass and weight

Today, I did some changes to my experiment as it is easier to work with some different materials than the ones I thought. So I looked for the balls I am going to use (a marble, a plastic ball, 2 balls made out of wood but with different sizes, etc). 

We are very happy witht he group and the work we are going to be doing.

Buthanol Graphs

Here we can see the table, the graph and the conclusion from the experiment of buthanol. To see the rest of the lab report go to previous pages (Wednesday, 19th February post).

Table showing how pressure in kPa varies with time in s.
Buthanol Graph

Time (s) (x)	Pressure (kPa) (y)
335.8	11.6
290	11.6
285	11.2
242.9	10.8
233.2	10.8
224.4	11.2
204.6	11.6
180.6	11.6
167.4	11.5
144.6	10.8
136.7	10.5
122.7	9.7
117.4	7.9
109.5	7.9
100	7.9
70	7.1
0	5.6

Graph showing how pressure in kPa varies with time in s.

Conclusion:According to the results of the table and the graph we can conlude that as time increases, the pressure of buthanol does too. At 0ºC, the pressure was of 5 kPa, after a determined time (increase of time) and with higher temperature (16ºC), the pressure increased to 7 kPa. As we increassed temperature and time passed by, the variation in temperrature continued until it reached 11.6 kPa. This is the maximum pressure of this substance. We continued increasing the temperature and time passed but the pressure started to decrease and then it increased again with 40ºC. As time passes the pressure of buthanol rises because as it is volatile, it goes from liquid to gaseous state, so particles spread and hit against walls more often, there was a slight decrease between second 150 and second 200, maybe due to a change in the temperature or human error. Observing the table and graph we can conclude that as time changes pressure does too. As time increases pressure increases. However, pressure reaches its maximum point in 11.6 kPA. It is a "barrier", because despite the fact that time continues to increase, pressure remains constant. Furthermore, it even decreases to 10.8 kPA, though after 40 seconds it increases again. 

SOLUTIONS LAB SESSION

NOTES FROM THE LAB:

mass and volume

electronic scale: number of figures after the coma

volume

Materials: volumetric flask, beaker, pipette, measuring cylinder

Volume of water: 10mL= 9.62g

C: Salt dissolves in water because of its chemical bonds.

PROCEDURE AND RESULTS

We took 10 mL of cyclohexane and 2.5 grams of sodium chloride. We poured them in the same dry measuring cylinder. The total volume was of 11.5 mL

The variation when we poured the NaCl was of 1.5 mL.

As it does not dissolve, we can work out the volume of the NaCl by measuring the change in volume of the mixture.

They didn’t dissolve so the mass was the same, so the volume will be the sum of both of them. The final volume was 11.5 mL. Volume of NaCl: 1.5 mL.

We see that NaCl doesn’t dissolve in hexane, but we will see that it does in water. Why? One of them (NaCl) is a polar molecule and the other one (hexane) is a non-polar molecule. Bonds.

“Matter cannot be created or destroyed, so mass is always conserved”. Our data agrees with this statement as the mass of hexane plus the mass of salt was the same as the mass of the solution:

Mass of hexane:

Mass of salt: 2.5 grams We sum them: ___

Final mass of the solution: ____

2. Is mass conserved when 2.5 g of salt is dissolved in water?

Weight a clean, dry 25mL measuring cylinder. 73. 68 grams

Take 10 mL of water with a pipette and pour it in the cylinder. Weigh it again, now with the water. 

What is the mass of the water? 10 mL of H2O weight 9.62 grams.

What should the mass of water be per gram? It should be 1 mL per gram but as it is not pure water we can observe that the mass is different.

Weigh 2.50 g of sodium chloride. Add it to the water and dissolve it.

Weigh the whole apparatus: 85.72 grams

Does the total mass equal the masses of the different parts?

Total mass: 85.72- 73.68= 12. 04 grams→ mass of the solution

mass of water: 9.62 grams, mass of salt: 2.5 grams. 9.62+2.5= 12.12

Is mass conserved? As we can see mass is conserved mostly, the 0.04 grams that varied may be due to human errors.

So mass is always conserved, but as we will see something different happens with volume.

What s the final volume of the solution?

3. Is volume “additive” (can we just add the individual volumes to get the final volume) when 2.5 g sodium chloride is dissolved in water? 

The volume of the mixture was smaller than the sum of both separately.

The answer is no, the volume of the water sums up to the volume of salt or sums up to the hexane is not the same as the total and final volume of the solution as in the final volume, salt is dissolved. This may have been because as the salt bonded with the water molecules, less space was occupied.

Demonstration:

What was the initial volume of water in part 2? 10 mL

What is the actual final volume of your sodium chloride solution? 11 mL. The final volume is different to the one we predicted, is less for the reason explained before. If 1 gram of NaCl is almost 1 mL of water (0.87 mL), the volume must be much more high if it was the sum of solute and solvent. The volume of salt should be 2.1 mL and the difference was of just 1 mL.

(11 mL , Vsolution, - 10mL ,Vwater, = 1 mL)