Some more on projectiles ... A few shortcuts
We all know the standard formulas for range, height and time of flight of a projectile. Consider a problem like this
A particle projected obliquely at 45 deg has a range of 16m. Find the maximum height reached by the particle.
Standard procedure:
Write the formula for Range
Evaluate u.
Find H.
Time taken: 2 min
Lets do summa new.
R = u2 sin2
/ g
H = u2 sin2
/ 2g
R/H = 4/tan
4H = Rtan
Use this relation
4H = 16 tan45
H = 4
Time taken :5 s
You get the idea. Similarly by doing R/T2 , H/T2 we get the following set of formulas
4H = Rtan
Rtan
=(1/2)gT2
H = (1/8)gT2
Now try solving these problems:
1. The range of a particle thrown at 45 deg is 8m. Find the time of flight.
2. The maximum height reached by a particle thrown obliquely is 2m. Find its time of flight.
Try solving these without using these simplifications once. You'll never let go of these then










