Forces and Angles
Question:

link for BLOSSOMS video : https://blossoms.mit.edu/videos/lessons/forces_and_angles

A vector is a quantity that has both magnitude and direction. Displacement, velocity, acceleration, and force are vectors.

In situations in which vectors are directed at angles to the customary coordinate axes, a useful mathematical trick will be employed to transform the vector into two parts with each part being directed along the coordinate axes. For example, a vector that is directed northwest can be thought of as having two parts - a northward part and a westward part.

The components of a vector depict the influence of that vector in a given direction. The combined influence of the two components is equivalent to the influence of the single two-dimensional vector. The single two-dimensional vector could be replaced by the two components.

If Fido's dog chain is stretched upward and rightward and pulled tight by his master, then the tension force in the chain has two components - an upward component and a rightward component.

Assume that the chain is exerting a 60 N force upon Fido at an angle of 40 degrees above the horizontal. A quick sketch of the situation reveals that to determine the vertical component of force, the sine function can be used and to determine the horizontal component of force, the cosine function can be used. The solution to this problem is shown below.

And now let's watch the video below, where two children are seen helping their father drag bags after work in the garden.

 

According to the above, why does the child in the orange shirt drag the bag more easily?

2 People tried to answer this question

He activates a smaller horizontal force.

He activates a smaller vertical force.

He activates a greater vertical force.

He activates a greater horizontal force.

The horizontal force component is the component in the direction of the movement and therefore when it is greater the movement will be faster

The horizontal force component is the component in the direction of the movement and therefore when it is smaller the movement will be slower

The vertical force component does not affect in the horizontal direction movement

The vertical force component does not affect in the horizontal direction movement



Comments:
1.  Hajir Reham (28.06.2017 am 11.20.10)
Peer Feedback - Forces and Angles

Hello Alaa;

First of all the introduction to the question is very clear and organized in a hierarchical and gradual manner, so that you first referred to the definition, and then added two detailed examples: the first one of vectors in general without formulas, and the second on the force vector with formulas, which makes it easier to refresh the background needed to solve the question.

Technically, the link to BLOSSOMS video could be made active by combining the link option in the editing specification of the question and then adding the link to the video.

I was very impressed and liked the video editing, short, interesting, and challenging to learn especially when adding "Let's freeze the video for a moment". Although the video is part of the Blossom video and we were asked to create a new original one. In this case since you have chosen to use a video which has been found on the net I would suggest you to specify where the video was taken and it has been processed by you. Or better yet to create something new and innovative that relates to your question. For example: to create an animation in which two objects are dragged at different angles that show the same principle.

The question you have formulated is indeed challenging and requires levels of thinking to apply and analyze based on the video in order to answer the question.

The formulas that come from the Pythagorean equation that you mentioned earlier indicate that there are basically three situations in which the child in orange manages to drag the sack more easily:

To be clear:

I will mark the child with the orange shirt as ORANGE and the second child with WHITE

Condition 1: When the magnitude of the force Vector operated by the two children has the same value, but the angle of the force Vector - which is operated by the boy who wears orange shirt is smaller:

Then: FhorizORANGE> FhorizWHITE

                                                                                                                        

Condition 2: When the angel of the force Vector - in which the children operate is the same but the magnitude of the force Vector - is greater by the boy who is dressed in orange shirt:

Then: FhorizORANGE> FhorizWHITE

 

Condition 3: When the magnitude of the force Vector is greater and the angle of the force Vector power is smaller which is operated by the boy who is dressed in orange shirt compared to the other child:

Then: FhorizORANGE> FhorizWHITE

 

The context of the question whose answer lies in the video appears the condition 1.

 Since the person who needs to solve the question has to rely on the video, it is necessary to clarify a few things in order to sharpen the question.

Therefore, a suggestion to improve the question is to add numerical values to the vector and especially the value of the angle to sharpen the difference in the angle of the force exerted by the two children. In other words a student who solves the question is not supposed to assume that the angel is smaller or bigger based on the vectors that were drown in the video, it supposed to be clear by adding an informative sentence that the angel which is operated by the boy who wears orange shirt is smaller. Since we as teachers always warn our students to draw conclusions about angles without numerical or comparative values.

 



History of edits
Edited BY: Alaa Khazim Edit Date: 2017-06-10 12:20:03
Edited BY: Alaa Khazim Edit Date: 2017-05-25 17:56:56
Created By: Alaa Khazim Edit Date: 2017-05-25 17:17:23
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