# Momentum Principle

1. Jan 17, 2013

### C R P

View the attached picture that is the problem that I need help with.

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Last edited: Jan 17, 2013
2. Jan 17, 2013

### SammyS

Staff Emeritus
Re: Momentum Priciple

Hello C R P. Welcome to PF !

We cannot give help without you showing your work or your reasoning as to why you gave your answers. (Also, you should not give solutions to other people who don not show work.)

Please explain why you checked or didn't check each answer. Please indicate what is expected of you on this exercise.

3. Jan 17, 2013

### Staff: Mentor

Re: Momentum Priciple

4. Jan 17, 2013

### C R P

Re: Momentum Priciple

Bloody Hell, I've done 2 years of physics but I'm just doing something wrong with problem yet it's so basic.

Any ideas on what I'm doing wrong!?!?

*Is this good?

5. Jan 17, 2013

### SammyS

Staff Emeritus
Re: Momentum Priciple

Not too bloody good.

Which items are you sure of?

Which are you not very sure of, and why did you give those tentative answers.?

6. Jan 17, 2013

### C R P

Ah it's too late now the home work was due at 11:59

I know Δp=FnetΔt and ΔP=mv

One question i do have is whether force parralel +force perpindicular are considered F net or not I feel like it should be F|| cross Fp

7. Jan 17, 2013

### SammyS

Staff Emeritus
Written as vectors, as in the very first item: Yes, force parallel +force perpendicular = force, probably net force, depending on the context

What is the difference between the following two statements?
$\displaystyle \vec{P}=\vec{F}_{\text{net}}\Delta t$

$\displaystyle \vec{P}_\text{f}=\vec{P}_\text{i}+\vec{F}_{ \text{net}}\Delta t$​
?