Introducing kinetic energy

Okay so ladies and gentlemen it's very much important that you indicate that the work done on an object you cannot just say the work done is equals to the kinetic energy okay so you need to state it in full uh you know in full weight so that it serves as a as a good indication that you come from a you know good hands okay so the net work done on an object is equal to they change a the change in kinetic energy of the object okay very very much important ladies and gentlemen remember this question is allocated to marks 

Ladies and gentlemen i'm i'm hoping you're very much happy with what i've just taught you that you can actually use the formula to state the theorem this is the net work energy done on an object okay this is equals to the change in kinetic energy of the object very easy and straightforward so by just stating that it gives you two marks okay very very much important ladies and gentlemen.

Remember the other one may decide to state the theorem in a different um you know way okay one may say the work done on an object by a net resultant force it's equals to the change in the objects kinetic energy okay so it's just a matter of you choosing the one that you feel like it's easy to state and you know the one that you feel like you won't forget you can just make use of that definition to answer related questions okay so ladies and gentlemen.

I'm not sure if let me just write it because uh you know in that way it gives you multiple traits in terms of choosing a which definition to use as an answer okay so that means the work done on an object by a net resultant force is equal to a change in the objects kinetic energy okay very very much important ladies and gentlemen by so saying this is how they give you your two marks okay.

Remember guys a if you want to have these definitions on record you can just listen to what i was saying don't necessarily need to uh try and read my hand writing okay it's not that much horrible but um i assume you're able to hear clearly what i was saying okay so ladies and gentlemen let's now move to the second question which is question five point okay very very much important ladies and gentlemen that you fully understand a question 5.1.

So now question 5.2 says draw a labeled free body diagram showing all the forces acting on the soldier while being lifted upwards very very much important ladies and gentlemen that you understand the question they want you to draw a free body diagram okay showing all the forces ladies and gentlemen all the forces acting on the soldier while being lifted upwards okay so guys i assume you fully know that you just make a dot there okay so what's going to guide you in terms of how to draw a free body diagram it's firstly what you see on the diagram and secondly uh what's going to guide you it's what is in the statement okay very very much important ladies and gentlemen.

So it's very much important that we firstly start with the obvious forces that we can see on the diagram okay so obviously we can see there's a force applied by the tension okay i assume everyone is able to see that then remember ladies and gentlemen they set a labeled free body diagram okay so you can just say force by attention or otherwise one can say force applied okay doesn't really matter whether you say a force by tension or otherwise you can just say tension it's a force okay so you will choose which one is suitable ladies and gentlemen we know at all times we always have force of gravity okay.

We always have force of gravity very very much important ladies and gentlemen otherwise you can just say wait okay because you know that's that soldier has got a weight ladies and gentlemen one is represented by this dot guys at all times when they say draw a free body diagram is because they know uh not everyone will be able to draw that soldier okay so it's not a a a chapter for you know as in culture where they they're interested in seeing you on how you draw okay so they just want you to represent that soldier by making a dot over there okay so that dot actually represents any object which is experiencing forces okay.

So ladies and gentlemen remember guys especially when it comes to this question where they want you to draw the free body diagram always take into consideration the marks allocated to that question okay as you can see this question is allocated three marks okay very very much important ladies and gentlemen three marks okay so guys it's in most cases where each force drawn is allocated a mark okay so obviously as you can see already have two forces drawn on that object okay so you now need the third force okay where do you get that third force remember by just looking at that diagram you know you can see you've got a force as a result of that tension as a result of that cable which is referred to as a force applied okay.

And again you know there's a gravitational a force or the weight which is always there so guys do we have any frictional force a or not very very much important ladies and gentlemen that we are able to tell if we've got a frictional force or not remember this is the force that you get from a statement friction is not to be ignored very very much important ladies and gentlemen affliction is not to be ignored okay in which direction is the air friction acting ladies and gentlemen is it acting in the upward or the downward direction relative to that soldier obviously the soldier is going up and we know friction is always opposing the direction of the movement okay so that object is moving upwards that means frictional force will be a opposing that soldier then you label it ladies and gentlemen.

Very very much important you label it you can just say fossil friction others they just use a small letter f then we know it represents a fractional force okay ladies and gentlemen this is how you easily score your three marks okay so this is how we we mark a your paper set marking center ladies and gentlemen we check if you have drawn a let me just do this if you have drawn your free body diagram and used the arrows okay this is what we check ladies and gentlemen did you use the errors very very much important because if you just do this okay we don't know in which direction these forces are acting maybe they are exiting towards that object.

Or maybe a they are acting in the in in those directions so that's why it's very very much important that a you know you make use of the arrows to indicate the direction in which the force it's being applied very very much important ladies and gentlemen and again and again guys it has to be labeled okay your forces or your errors or your lines has to be labeled that's why they say a labeled free body diagram okay do not just leave it like this but make sure that you label it so you normally have force applied you have force of gravity you have a you know fossil friction and you might also have just like a there actually tension and force applied sometimes they just choose to use tension in some questions it could be force applied okay very very much important ladies and gentlemen that you are aware of those type of forces so i assume we are all on the same page on this question ladies and gentlemen i assume all of you are confident and if this question comes i'm 100 sure that you guys you won't disappoint a and again i assume you will be able to fully answer the question and score maximum marks...