Secondary I • 2yr.
Can you help me in the following exercise:
"Name the different effects of forces:
- We push on a concrete block
- We pull on a rope
- We twist a rag
- We press on a plank of wood held by two blocks
- We tear a piece of fabric ”
Explanation from Alloprof
This Explanation was submitted by a member of the Alloprof team.
Thank you for your question!
First, the question asks you to assign different effects of forces to the actions described. These probable consequences are the following: crushing, elongation, torsion, bending, and shearing.
In the first example, the action of pushing on the concrete block slightly crushes the object. Admittedly, this is not the best example, but it is the only logical choice compared to the others.
As for the second example, pulling on a rope tends to make it stretch. An extension takes place. Therefore, the effect is elongation.
In the third example, the rag is subject to two rotational forces in opposite directions. This question truly is a twist! Therefore, torsion is the correct answer.
As for the fourth example: the wooden board is subject to several compressive forces, which cause it to bend in several places. Therefore, the effect is bending.
In the fifth example, the piece of cloth tears because of two parallel adjacent forces in opposite directions. Therefore, the effect is shear.
In short, the trick to answering this type of question is to understand the forces applied so that you know how to identify the effects of their interactions.
Do not hesitate if you have other questions!