Graph paper: When you need graph paper and you do not have the type you really want, then visit these pages and print out what your heart desires. Graph paper link 1 Graph paper link 2

TOPIC 1:

Here is the PP presentation that I promised... the credit for this presentation belongs to someone else and not me (once I will find who made this I will add his/her name here)

University of Colorado at Boulder has several simulations on their web page. In this "The Moving Man" -simulation you can play with distance-time, velocity-time and acceleration-time graphs.

Forces: A lot of these videos are from Khan Academy. It is place to visit!!!! Here are some samples for you to see;

Friction: In this video (Kinetic friction) teacher shows a way to measure kinetic friction. The ideas is that if the object moves with no acceleration then the resultant force acting on the object must be zero newtons. If it takes 3 N (forwards) to keep the object moving like this, then there has to be a force, now called friction, that is also 3 N and points backwards.

More about friction, now on an inclined plane. Please note that the normal force is not the component of the gravitational force that goes "inside the inclined plane" but is actually pointing up from the surface ( and is the same size as the before mentioned component of the gravitational force). I think that the teacher in the video made a mistake in that part so listen carefully.....

1) The acceleration of the "whole 10 kg block" has to be the same as the acceleration of each separate block. This is so as they all move together and not one is moving slower of faster than the others. The acceleration can be calculated by: a= F/m= 20N /10kg = 2 m/s^2.
2) Let us look into the case of the first 2 kg block. All the other blocks will go through the same treatment later on.
3) There are two forces acting on the 2 kg block. 20 N force to the right and the force by which the 3 kg block is pushing the 2 kg block to the left. These two forces must, when added together, form a resultant force that is responsible for the 2 m/s^2 acceleration for the 2 kg block. This means that the resultant force acting on the 2 kg block has to be 2m/s^2 *2 kg = 4 N to the right. If the force acting on the 2 kg block to the right is 20N then the force acting on it to the left has to be 20N - 4N =16 N. This 16N is the force by which the 3 kg block is pushing the 2 kg block. PROBLEM SOLVED!
3) When you look into the case of 3 kg then the forces acting on it are 16N towards right and force from the 5 kg block. You can find the latter force with the same treatment as in the first block, etc.

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GENRAL HELP:Graph paper: When you need graph paper and you do not have the type you really want, then visit these pages and print out what your heart desires.

Graph paper link 1

Graph paper link 2

TOPIC 1:TOPIC 2:HELP FOR REVISION!!!!!Page 85 Question 13:

1) The acceleration of the "whole 10 kg block" has to be the same as the acceleration of each separate block. This is so as they all move together and not one is moving slower of faster than the others. The acceleration can be calculated by: a= F/m= 20N /10kg = 2 m/s^2.

2) Let us look into the case of the first 2 kg block. All the other blocks will go through the same treatment later on.

3) There are two forces acting on the 2 kg block. 20 N force to the right and the force by which the 3 kg block is pushing the 2 kg block to the left. These two forces must, when added together, form a resultant force that is responsible for the 2 m/s^2 acceleration for the 2 kg block. This means that the resultant force acting on the 2 kg block has to be 2m/s^2 *2 kg = 4 N to the right. If the force acting on the 2 kg block to the right is 20N then the force acting on it to the left has to be 20N - 4N =16 N. This 16N is the force by which the 3 kg block is pushing the 2 kg block. PROBLEM SOLVED!

3) When you look into the case of 3 kg then the forces acting on it are 16N towards right and force from the 5 kg block. You can find the latter force with the same treatment as in the first block, etc.