A projectile is shot from the ground at a velocity of #19 ms^-1# and at an angle of #(2pi)/3#. How long will it take for the projectile to land?
Initial velocity in the y direction,
The approach to solving projectile motion problems is to divide the motion into its horizontal component,
This just means the initial velocity in the
To solve this particular problem, we divide the trajectory into two equal parts: before the projectile reaches its maximum height and after. These two parts will take the same amount of time.
We use the fact that the velocity in the y direction falls to
Rearranging to make
(the acceleration due to gravity is shown as negative because it is in the opposite direction to the initial velocity)
Crucial to remember - students often forget this in the exam - that this is the time for only half the trajectory: the object still needs to return to earth. Double this time and the final answer is