Help

[CatMeoooow]

Can someone solve and explain question 3 for me?
http://www.vcaa.vic.edu.au/vce/studies/physics/pastexams/2007/2007physics1.pdf

[Lasercookie]

Question 3 of what section? Motion? Electronics/Photonics? One of the detailed studies?

I'm going to assume you're doing Unit 2 and currently covering motion.

This is just a conservation of momentum question.

You're given information about the system before, and the system after. You have the masses and the velocities, and hence can calculate momentum.

You should be familiar with this expression. If you're not, have a read of the textbook, and point out to us what you don't understand. On the off chance that you weren't asking about motion, I'm just going to take the safe option and give you this recent thread as reading material: Help! Momentum





Let's set m_1 to be the 2kg block, and the m_2 to be the 1kg block. Essentially, just substitute in the values you know already, and solve for v_1.

[CatMeoooow]

Is this correct. 

(2)(3)+(1)(0)=(2)(v1)+(1)(4)   

Which I then substituted to         

(2)(3)+1/2+4   

which gave me an answer of 1m/s 

[Lasercookie]

(2)(3)+(1)(0)=(2)(v1)+(1)(4)   

You've done the first step correct.

(2)(3)+1/2+4   

With the second step, I'm not sure what you've done here, or what you did to get 1 m/s out of it. Did you make a typo, since

[paulsterio]

Is this correct. 

(2)(3)+(1)(0)=(2)(v1)+(1)(4)   

Which I then substituted to         

(2)(3)+1/2+4   

which gave me an answer of 1m/s 

First of all, please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please please pleaseeeee write down the formula whenever you're making a calculation. I know that you don't have to and I say so in my book too, but just please do it - like it just annoys me to no end when you don't write the formula. You're just potentially confusing yourself and you're not allowing yourself to gain any marks if your answer is incorrect (they will give a mark for correct formula stated). So just please write down the formula.








P.S: That's enough 'pleases' right?

[paulsterio]

Thanks Thushan