1. REQUIREMENTS

Produce a computer program, written in the Ada programming language, which determines the distance travelled by a projectile (projected from the ground) given:

1. Velocity at launch (u), and
2. Launch angle (angle of elevation) above the horizontal (A).

Assume the following:

• The launch velocity is within the range 100 to 400m/s.
• The angle of elevation is given in degrees within the range 0 to 90.
• Assume gravity (g) is equivalent to 10m/s^2.
• The result is to be output accurate to 1 decimal place (i.e. 1/10th of a metre).
• Ignore air resistance.

Note also that to solve the above we must carry out the following steps.

1. Calculate the vertical and horizontal components of u (the launch velocity) using the following trigonometric identities:

   Vertical component of launch velocity  (Vu) = u x sinA
   
   Horizontal component of launch velocity (Hu) = u x cosA
   

   
2. Calculate the time (t) taken for the body to return to the ground using the identity:

   t = (2 x Vu)/a
   

   where a (deceleration due to gravity) is equivalent to g (10m/s^2 in this case).
3. Calculate distance (s) travelled from the identity:

   s = Hu x t
   

2. EXAMPLE

A body is projected with a velocity of u = 200 m/s at an angle of elevation A = 30 degrees above the horizontal. Determine the distance travelled by the projectile.

Vu  = 200 x sin30 = 100 (m/s)

Hu = 200 x cos30 = 173.2 (m/s)

t = {2 x 100)/10 = 20 (s)

s = 20 x 173.2051 = 3464.1 (m)

3. REPORT

You should hand in a report comprising the following sections:

1. Outline of the above requirements
2. Design - including top down analysis and N-S chart(s)
3. Implementation
4. Test cases (BVA, limit, arithmetic and data validation) and results

Refer to guidance notes on the presentation of work if necessary. You might also like to refer to the vertical motion example studied in week 5.

Created and maintained by Frans Coenen. Last updated 11 October 1999