Free fall and his effects on water splash

Objective:

To prove the difference of loss of water when throwing a ball in free fall from diferent heights and measuring how much water went out of the beaker.

Background information:

Free fall is what we call when an object is falling because of the force of gravity (9, 8 m/s² each second). When an object is in state of free fall, this one will accelerate according to gravity acceleration number wich has been said before. If we want to calculate the final velocity or any other reult affected by gravity, we use to use these equations called the kinematic equations:

v­_i = Inicial velocity           v_f = final velocity

t = Time (in seconds)      a = acceleration (9, 8 m/s²)

d = distance

Images and information took from 

Physicsclassroom.com

Kinematic Equations

In-text: (Physicsclassroom.com, 2014)

Bibliography: Physicsclassroom.com, (2014). Kinematic Equations. [online] Available at: http://www.physicsclassroom.com/class/1DKin/Lesson-6/Kinematic-Equations [Accessed 26 May. 2014].

Hypothesis:

The hypothesis is that when higher is the ball, more water will come out of the beaker because of the force of the impact.

Variables:
Independent: Height from where we throw the ball
Dependent: Loss of water in the beaker
Controlled: Mass of the plasticine ball

Materials:

- Waterproof scale

- Beaker of 10/15 cm of diameter

 - Plasticine ball

- Ruler

- Water

Procedure:

1. Fill the beaker with water.

2. Measure the weight of the water in the beaker

3. Throw the plasticine ball from 30 cm and meaure the lss of water (and so weight) done by the splash.

4. Repeat this process 2 times.

5. Do the same than in point 3. and 4. but at 50 cm

6. Then with 70 cm, 90 cm and 110 cm.

7. Put the results in a table and make the average between the three throw at the same height.

	Attempt 1 (mL)	Attempt 2 (mL)	Attempt 3 (mL)	Average
30 cm	4.2	4.6	4.2	4.3
50 cm	8.2	9.8	7.8	8.7
70 cm	14.8	13.2	15.0	14.3
90 cm	21.8	21.2	23.8	22.3
110 cm	19.8	22.4	20.6	21.4

Conclusion:

1.      We can observe that the more potencial energy we have the higher the water lost is. This is due to the fact that this potential energy it´s transformed into kinetic energy which is passes to the water which makes it move and some of it  goes out.

2.      Another thing we can see is that it is directly proportional. From our data  we can guess it forms a curve but we know that it´s not going to go to infinity since there´s a finite amount of water. Therefore it must be a hyperbola which tends to 1.3340 L (Our amount of water) when x goes to infinity and to 0 when it goes to –infinity

3.      We have to take into account our equipment is not perfect and maybe that´s why for example in 110cm we had some strange results compared with the ones we got on 90cm which is strange but it may have been cause the difference between this two is small and one has gone a bit up and the other a bit down.

b    We couldn´t be exact in the height despite having a device to measure so it can change +- 5 cm

2.      We couldn´t be sure if we threw it exactly in the centre of the bowl and this can have a big repercussion in the amount of water that goes out.

Precision of measurement

Materials:

Measuring Cylinder            

Pipette

Volumetric flask

NaCl (Common Salt)

Hexane

Procedure:

Test 1:

1.Get a an empty measuring cylinder.

2. Weight it, it had a total weight of 77.8 g.

3. Use the pipette and the measurement cylinder to put 10 ml of water.

4. Pour the water on the measuring cylinder.

5. Weight the total mass.

6. Subtract the mass of the measuring cylinder to the total and you will have the weight of the water. (9.43g)

Test 2:

1.       Use the same measuring cylinder (which weights 77.8g) to introduce 2,5 grams of NaCl (table salt).

2.       Weight it with the salt in it.

3.       Do the same equation in order to obtain the mass of the solution.

Conclusion:

We have seen how NaCl has dissolved in water but not in hexane, this is because NaCl and water are both polar substances so they can dissolve easily while hexane is a covalent bond and water, as we have said, is polar so it is very hard to make them dissolve.

By doing this work, we learnt how to accurate more our results and that, even if we with the higher accuracy possible, it wasn't perfect. For the next time I think that we could try to be more precise, take more notes and photos of absolutely all in order to have good images to explain the experiment.

Pressure of Ethyl Acetate

Background information:

The Ethyl Acetate or C4H8O2 is a chemical that have a caracteristic sweet smell, it is used in glue, edcaffeinating tea and cofee and also used in cigarettes. This chemical has no special color, it is like water. The Ethyl Acetetate is made of Acetic acid and ethanol.
The pressure is the unit of force that we use to mesasure the force that have a gas in a particular volume, if we reduce the volume but not the cuantity of gas, the pressure and if the volume is bigger the pressure will be lower.

Procedure:

1. Select a chemical (In our case it will be the Ethyl Acetate)

2.  Set up a shlenk tube with 5ml of your chemical inside

3.

4. Attach the pressure sensor and make vacuum inside

5. Record the vapour pressure of your chemical at four different temperatures using logger pro.

6. Clean the shlenk tube and pack it away.

Conclusion:

When higher is temperature, more volatility it will have because the particles move faster due to the energy given by temperature, So, if the Ethyl Acetate particles are  more separated from each other, this will lead to a lower pressure.