x Turn on thread page Beta
 You are Here: Home >< Maths

# Maths mechanics watch

1. A particle B of mass 0.3kg is moving with velocity (7i+4j)m/s when it collides with a stationary particle C of mass 0.5kg. immediately after the collision C moves with velocity (6i+0) m/s.

a) find the velocity of B immediately after the collision.
b) find the speed of B immediately after the collision
2. how far did you get harry ?
3. (Original post by harrybo6)
A particle B of mass 0.3kg is moving with velocity (7i+4j)m/s when it collides with a stationary particle C of mass 0.5kg. immediately after the collision C moves with velocity (6i+0) m/s.

a) find the velocity of A immediately after the collision.
b) find the speed of A immediately after the collision
You must've learned the equation m1u1 + m2u2 = m1v1 + m2v2 right?
m1 is the mass of particle B
m2 is the mass of particle C
Can you tell me what v1,v2,u1 and u2 are? If so just plug them into the equation.
4. You didnt mention a particle A but if you got your letters wrong you can just use conservation of momentum.
5. (Original post by ComputerMaths97)
You must've learned the equation m1v1 + m1u1 = m2v2 + m2u2 right?
m1 is the mass of particle B
m2 is the mass of particle C
Can you tell me what v1,v2,u1 and u2 are? If so just plug them into the equation.
i can tell you what i did but im not sure if im right! i did 0.3x(7i+4j) which i got
2.1i+1.2j = before momentum
after momentum =2.1i+1.2j = 0.3v + 0.5(6i) = 0.3v+3i
so i rearranged moving 3i over -0.9i+1.2j = 0.3v devided by 0.3
=-3i+4j
thats what i got for part a) but part b i have no clue i thought they were the same, so i just squared 3 and 4 then took the sqare number of that which got me 5
6. (Original post by CheetahCurtis)
You didnt mention a particle A but if you got your letters wrong you can just use conservation of momentum.
sorry didnt see that, thanks for letting me know
7. (Original post by harrybo6)
i can tell you what i did but im not sure if im right! i did 0.3x(7i+4j) which i got
2.1i+1.2j = before momentum
after momentum =2.1i+1.2j = 0.3v + 0.5(6i) = 0.3v+3i
so i rearranged moving 3i over -0.9i+1.2j = 0.3v devided by 0.3
=-3i+4j
thats what i got for part a) but part b i have no clue i thought they were the same, so i just squared 3 and 4 then took the sqare number of that which got me 5
Perfect!
8. (Original post by ComputerMaths97)
Perfect!
Thank you

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 23, 2015
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams