# A particle P is projected from a point O with velocity

1. Feb 8, 2012

### VICKZZA

1. The problem statement, all variables and given/known data
A particle P is projected from a point O with velocity 12i +16j .two seconds later,another particle Q is projected from O and collides with P after another second.Find the initial velocity of Q.

2. Relevant equations

x=(vcosθ)(t)
y=vtsinθ-1/2gt^2
3. The attempt at a solution i think that Q will approach P when ts vertical and horizontal distance become equal with P.but i cant handle the time change or its accurates valuess.......plzzz help me out..............

2. Feb 8, 2012

### Staff: Mentor

Re: Projectiles

How many seconds does the first particle spend in flight before the collision? What is the x,y location of the collision?

3. Feb 8, 2012

### VICKZZA

Re: Projectiles

its not given in the question

4. Feb 8, 2012

### Staff: Mentor

Re: Projectiles

Sure it is. Reread the question statement carefully.

5. Feb 8, 2012

### VICKZZA

Re: Projectiles

its not there

6. Feb 8, 2012

### OJFord

Re: Projectiles

Yes, it is.

P is projected. 2 seconds later, Q is projected. Another second later, they collide.

Collision happens, 2 + 1 = 3 seconds after P is projected. From there, you should be able to easily work out the location of collision (where is P 3 seconds after projection?).