Question

Place a chair against a wall so it cannot be slid back. Have one student sit in the chair
with their feet flat in front of the chair. Place your thumb on their forehead and ask
them to stand up. Why does the student struggle to stand

Answer 1

We will see that the student struggles to stand because of the angle that his/her legs form and because of the downward force that your thumb makes.

Why does this make it harder to stand up?

First, think that when you stand up, your legs (and also your abdomen) are lifting a lot of weight. When the student is in the given situation two things happen.

1) The thumb in his/her head causes a downward force when the student tries to stand, making it harder for the legs and the abdomen to lift the weight.

2) By not allowing the chair to move, the student must make this force when his/her legs are forming a 90° angle, because of this angle the force needed to lift the weight is larger.

So for these two reasons, the student will struggle to stand.

If you want to learn more about forces, you can read:

https://brainly.com/question/13370981