Why use conservation of mechanical energy for aircraft landing and falling ball

[Titan]

I selected two motion problems:

1) Aircraft landing
2) Ball falling onto the gound

Using conservation of mechnical energy principles I need to fully expain and justify my reasons why its more suitable than applying Newton's laws of motion.

I have already said
a) Newton laws of motions assumes no energy losses
b) Conservation of machnical energy - energy is transfers into other energy.

but what else can I say or how can I expand my reason?


thanks in advance

 

[mgb_phys]

Sorry can you try and say what the question is?
Are you asking, when is it more practical to use conservation of energy and when is it more practical to use Newton's laws to answer a mechanics queastion?

 

[Titan]

Sorry can you try and say what the question is?
Are you asking, when is it more practical to use conservation of energy and when is it more practical to use Newton's laws to answer a mechanics queastion?

Yes in a way. What I need to do, is to explain why its better (more suitable) to using conservation of mechanical energy principles to apply to the two motions rather then using Newtons laws of motion.

The question, which I was given were to describle two motion problems (of my choice, could be anything sort of problem) It's not asking me to physically solve the problems but rather to explain. I haven't yet fully explain and justify my reasons, that was I need help.

 

[mgb_phys]

Conservation of energy has the advantage that it is always right for simple physics problems where you neglect friction etc. So initial KE equals PE at the top of the curve = KE at the ground for a projectile. You don't have to do any force diagrams and you can't really get the signs wrong.

But conservation isn't always enough to answer the question such as when you have to describe the direction something will go in. Newton's laws give you more rules for what happens, conservation is a good check - if it is violated you have gone wrong somewhere.

 

[Titan]

Conservation of energy has the advantage that it is always right for simple physics problems where you neglect friction etc. So initial KE equals PE at the top of the curve = KE at the ground for a projectile. You don't have to do any force diagrams and you can't really get the signs wrong.

But conservation isn't always enough to answer the question such as when you have to describe the direction something will go in. Newton's laws give you more rules for what happens, conservation is a good check - if it is violated you have gone wrong somewhere.

Ok. Are there other advantages of Conservation of energy over Newton's laws of motion?