# Homework Help: M2 question

1. Jun 30, 2008

### i25959341

1. The problem statement, all variables and given/known data

some ocr m2 questions

2. Relevant equations

-
P]
]
]
]
b]
]
]
]
]
O]-----------------------------------------------Q
x

A BULLETis fired at position P with speed âˆšag (g=9.8) at an angle z above the horizontal, where a is a constant. P is at vertical height b ablve the horizontal plane. The bullet strikes the plane at the point Q and O is the point at the level of the plane vertically below P, as shown. Letting OQ=x

x^2 tan z - 2axtan z +( x^2 -2ab) =0
show maximum value of x as z varies is âˆš a(a+2b) and that is archieved when Tan Z =âˆš a/a+2b

3. The attempt at a solution

2. Jun 30, 2008

### calef

What direction do you think you need to take this problem?

3. Jun 30, 2008

### i25959341

erm the equation look like the trajectory
the problem is these quations assumsed that the partical is on ground level, so shud i just do it that way then?? or make adjustment to the equations given like greatest height reached , time returning to its originalheight and range on horizontal ground??
y= ut +0.5gt^2

4. Jun 30, 2008

### calef

Don't assume it's on ground level.

The tricky thing about trajectory is that the angle which gives the farthest horizontal distance at any given velocity is below 45 degrees when you raise the launch platform.

It's not much more difficult to solve as if it were on the ground, though. Just account for the elevation, b.

5. Jun 30, 2008

### i25959341

can u explain to the trajectory equation and its signifigance and stuff cos i am doing M2 myself without a teacher so i m finding it difficult to grasp some of the important concept and implications from the equations. like how to use it and why??