Can you talk me through how to solve problems on projectiles? I always get confused
The strategy is to consider the horizontal and vertical components of the motion separately, and use the equations of motion in each direction. A few things to remember are: the vertical acceleration is always -9.8 ms-2 (due to gravity), the projectile will continue to move upwards until the vertical component of its velocity is zero, the horizontal acceleration is always zero and the horizontal velocity is constant.
do you remember what the equations of motion are?
v = u + at, 2as = v2 - u2 and s = ut + ½at2
There are various quantities that you are commonly asked to find.
1) Time to the highest point: use v = u + at vertically, with v = 0
2) Greatest vertical height: use 2as = v2 - u2 vertically, with v = 0, or use s = ut + ½at2 if the time is known
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Time taken for it to reach a particular height: use s = ut + ½at2 vertically (if it is returning to the same height at which it started - eg returning to the ground - take s = 0)
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Total horizontal distance travelled find the time taken for it to finish its journey (as above), then use s = ut horizontally
Do these rules make sense? Now lets look at some sample questions.
