2) Science Investigation

1.  OBJECTIVE

1a. Learn how an inclined plane works.

 

First of all, the inclined plane is of the many simple machines including the wedge, athe lever, the wheel, the screw, and the pulley. The inclined plane is used to lift things easier. Lifting an object straight up is using more force than pulling the object against an inclined plane, which uses friction. The position of how the ramp is positioned is called the slope or the gradient in mathematical terms. As the slope gets steeper, the force that is used to lift the item gets closer to lifting the item straight up. Like the picture, if you say that the above angle is  (theta), as theta increases the slope becomes steeper as the item becomes harder to loft and it gets closer to the weight of lifting the item straight up. On the other hand, as theta decreases, it becomes easier to lift.

 

1b. Investigate how the force to pull a load up an inclined plane depends on the slope of the incline.

 

2.  INTRODUCTION

You will begin your investigation of machines by focusing on the inclined plane.  Inclined planes are ramps.  You see them everywhere.  Many places have ramps to help physically disabled people enter and exit buildings.   Sometimes people use ramps to move heavy loads.  If you had to raise a heavy load to some height, would you rather lift it straight up or push it along an incline?  Think about that as you do this inquiry.

 

2a.  Have you every seen a ramp used to move an object or a person to a higher position?  If so, where?

 

I have seen a lot of ramps used in everyday life. In malls or public areas, there are a lot of stairs and for people who are using wheel chairs it might be harder for them to get up the stairs. That is why they have stone ramps next to the stairs so that those people can get up the same height not having any trouble. Also carts from the markets can often use these routes. Another ramp that I have seen in was when people move from house to house. Some boxes are very heavy and they are not able to move up by hand. That is why they have ramps so they can use less force to carry the item. One last way of the many there are car ramps. Car ramps are used when you want to fix the car, or make it go up on something. Then you don’t have to lift the car up and you can just roll the car.

 

2b.  Did the ramp have a gentle slope or a steep slope?

 

Even though they are different types of ramps, they all have a similarity that they all had a gentle slope. There is no use using a steep slope because it makes the whole process harder because more force is required to move the item. If it is a gentle slope however, you can move the item more easily and smoothly without a problem.

 

2c.  Why do you think a ramp was used?

 

A ramp was used because it used up less force than just moving the ramp up. As mentioned previously, we have to use a ramp with a gentle slope because there is no use using a steep slope.

 

3.  MEASURING FORCE ON AN INCLINED PLANE

 

3a. Attach a spring scale to an object and measure the force required to pull the object at a slow, steady speed across a flat-lying shelf board.

 

Item used: Full water bottle

Effort Force: 0.75 Newtons

b

3b. The force you used to pull the object is called the effort force. 

 

3c. Place the object on an inclined plane (Raise your shelf board to any height).  Measure and record the effort force required to hold the object on the inclined plane.  How much force did you measure?

 c

Effort Force: 1 Newton

Rise: 28 cm

 

3d.  If you pulled the object up the plane (instead of just holding it in one position), how do you think the effort force needed to pull the object up the incline at a slow, steady speed would compare with the effort force needed to move the object across the flat-lying shelf board?

 

Hypothesis: My hypothesis is that the effort force needed to pull the object up the inclined plane will take more force than the effort force needed to move the object across the flat-lying shelf board because the gravity is pulling it down while the flat one isn’t.

 

3e.  Test your prediction and record results.

 

 

Rise

Run (cm)

Slope (cm)

Effort Force (Newtons)

Flat lying board

0 cm

89 cm

0

0.75 Newtons

Inclined Plane

28 cm

83 cm

0.34

2.1 Newtons

  

3f.  What do you predict will happen to the effort force required to move the object up the inclined plane if the slope (steepness) of the inclined plane is changed (both increased and decreased)?

I think that if the inclined plane’s slope is increased the effort force required will increase because the gravity has more force when it is getting close to being vertical.

 

3g.  Design a procedure to test your prediction.  To measure the different slopes of the inclined plane in your experiment, please see the diagram below, measure the “rise” and the “run” and record the slope as the “rise” divided by “run.”  

d

3h.  Write your procedure here.  

 

a) Variables

a) Variables

 

Independent variable: The independent variable is the slope (rise/run)- We are changing the slope purposely by changing the rise (books) and the run to meet the slope we want.

 

Dependent Variable:

–       Effort force: This is the one that is going on the graph

–       Angle or theta: This can be the dependent variable in another experiment.

Control Group:

–       The thickness of the books

–       The weight amount of water in the water bottle.

 

b) Materials Needed

– Filled water bottle

– 6 Books

– ramp

– meter stick

– Spring Scale

e

c) Procedure

 

1)    Fill up the water bottle.

2)    Get out the six books, meter stick, the Spring scale, and the ramp.

3)    But the ramp on the flat surface and slowly move the water bottle on the spring scale across.

4)    Record the rise, run, and the effort force.

5)    Calculate the slope.

6)    Put one book below the ramp and slowly move the water bottle on the spring scale across.

7)    Record the rise, run, and the effort force

8)    Calculate the slope

9)    Put another book (so there is two) below the ramp and slowly move the water bottle on the spring scale across.

10) Record the rise, run, and the effort force.

11) Calculate the slope.

12) Put another book (so there is three) below the ramp and slowly move the water bottle on the spring scale across.

13) Record the rise, run, and the effort force.

14) Calculate the slope.

15) Put another book (so there is four) below the ramp and slowly move the water bottle on the spring scale across.

16) Record the rise, run, and the effort force.

17) Calculate the slope.

18) Put another book (so there is five) below the ramp and slowly move the water bottle on the spring scale across.

19) Record the rise, run, and the effort force.

20) Calculate the slope.

21) Put another book (so there is six) below the ramp and slowly move the water bottle on the spring scale across.

22) Record the rise, run, and the effort force.

23) Calculate the slope.

24) See the results and make a graph.

 

3i.  Make a data table to record your measurements here.  It should include Rise, Run, Slope, Effort Force

 

Try

Rise

Run

Slope

Effort Force (Newtons)

0 Books

0 89 0 0.4

1 book

4 88 0.05 0.8

2 books

8 87 0.1 1.2

3 books

12 86 0.14 1.6

4 books

16 85 0.2 2.0

5 books

20 84 0.24 2.4

6 books

24 83 0.3 2.8

 

 

3i.   Perform your experiment and collect your data.

 

3j.  Graph and describe your data.  What does trend (=pattern) does the graph show?  (How does the data change?)

 m

We can see more data on the table so I will explain about the table. In the table the things that are shown and marked are the rise, run, slope, the number of books, and the effort force in newtons. We can analyze that as the number of books increases the rise becomes higher, the run becomes lower, and the slope and the effort force becomes higher. For example when we had 1 book we had a rise of 4cm and a run of 88cm. We also had a slope of 0.05 and a effort force of 0.8 Newtons. However, when we had 2 books we had a rise, run, slope, effort force of 8cm, 87com, 0.1, and 1.2 Newtons, respectively. This shows us that the thickness of the books are 4 cm and that as we add more books the rise increases by 4 cm, the run decreases by 1 cm, the slope increases in about 0.05, and the effort force increases about 0.4 each time. While in the table we find out the difference between the individuals, in the graph we find out about the patterns that it shows.

 

In the graph the slopes are in decimals so we can only see about where the points are on the graph and we can’t call out the coordinates. However, we can see in this graph that overall as the slope increases the Effort force (Newtons) increase as well. Also sometimes the slopes aren’t the same distances with the other points. Some of them are closer.

For an extra part I not only wanted to compare the graph to the table but I wanted to compare two graphs:

 

1) Graph without line of best fit

m

2) Graph with line of best fit

Newetons2

 

These two graphs are nearly the same but the only difference is that the last one has a line of best fit. The line of best fit is a linear line that creates an over all relationship between the two variables, in this case Slope and effort force in newtons. Now the question that we have to answer is this: which one is easier to use? I would say that the graph with the line of best fit is easier because you can see the overall increase in the points, which is labeled, as series 1. Now that we have a linear line supporting, it is easier for us to tell if it is increasing or not. The first one is not as effective because it only has points and we can’t actually tell if it is linear or if it is slightly off.

 

3k.  Present a conclusion supported by your data about the effort force needed to move the object along the inclined plane and how it relates to the slope of the inclined plane.  Include an explanation for the relationship you find.

 

To answer the overall question, in the experiment we found out about the relationship of slope to the effort force in Newtons. As the number of books or the rise increased the run decreased which means that the numerator is getting bigger than the denominator making the number become bigger every time. As the slope becomes steeper, the effort force becomes larger because it is coming close to the object just hanging from the sky, which is the position that takes up the most effort force. Therefore, with my experiment, I proved that as the slope becomes steeper the effort force increases as well.

 

In my Hypothesis I stated:

I think that if the inclined plane’s slope is increased the effort force required will increase because the gravity has more force when it is getting close to being vertical.

 

I have proved my self exactly because in my experiment, as the slope increased the effort force increased as well. The reason was the same too because it was getting close to the point where gravity takes over and when it is just hanging from the sky.

 

Rise/run is called the slope or the gradient. Rise is the numerator and run is the denominator. If the numerator is smaller than the denominator, then the number is going to be a fraction and vise versa. In this case, the numerator is getting bigger and bigger and the denominator is getting smaller which means that the overall slope is going to increase throughout. Also we can measure the slope with an angle called theta. Because the triangle formed with the ramp is a right triangle, we can know that as theta increases the slope becomes steeper. The highest that a slope can go is 90 degrees which is just holding it from the sky which proves that it is the maximum. Also this deals with gravity. As we pull it up steeper slopes the gravity seems to “pull” harder on the water bottle making it harder to lift up. We have experimented that if we pull the bottle from the air this is the maximum amount of effort force used. As the slope becomes steeper it gets closer to this amount.

n

Explanation of the drawing:

 

The dashes on the side of each book mean that the height of them are the same, in this case, they are all 4 cm. I have marked the rise and the run so that people can clarify how to measure them. Also I have marked the theta angle, which is explained about the conclusion. I have noted that rise/run is the slope. This is a very important fact that everyone should know. I wrote on the bottom that as theta gets smaller the effort force decreases as well. Also I wrote as the slope increases, effort force increases. All of these facts are included in the Conclusion.