Kinematics Problem

[Prince Ibz]

Ok so I have this question in my book; "A particle P is projected vertically upwards from a point O with speed 12m/s. One second after P has been projected from O, another particle Q is projected vertically upwards with speed 20m/s. Find a) the time between the instant that P is projected from O and the time instant when P and Q collide, b) the distance of the point where P and Q collide from O." My book just states the answer at the back to be a) 1.4s and b) 7.2m I worked out the question in every way possible, but I just can't obtain the correct answer... any help greatly appreciated

 

[tronicgirl388]

Hope this helps

 

[Prince Ibz]

Thanks, it helped a lot really. I left that question out and had actually proceeded to the next chapter. I forgot all about it