In the previous example of time of flight, the out of control bus is forced to jump from a location ⟨0,40,−5⟩m with an initial velocity of ⟨80,7,−5⟩m/s−1. We have now found the time of flight to be 3.65s and now want to find the position of where the bus returns to the ground.
Diagram of forces acting on bus once it leaves the road.
The general equation for calculating the final position of an object:
→rf=→ri+→vavgΔt
Also know as the position update formula.
From the previous problem you already know the final location of the ball in the y direction to be 0 as it has met the ground after 9.59s.
We now to find the range in the x and z directions in order to have a position vector for the final resting place of the bus.
There is no force acting in the x or z directions as the only force acting on the system is the gravitational force which acts in the y-direction.
This means that the initial velocities in both of these directions have remained unchanged.
We know the amount of time the bus has been traveling in the x-direction at its initial velocity and its initial position so we can compute the distance travelled in this direction using the position update formula for x-components.
xf=xi+Vavg,xΔt
Plug in respective values for variables.
=0+80m/s(3.65s)
Compute range in x-direction.
=292m
Repeat same process for the z-components:
zf=zi+Vavg,zΔt
Plug in respective values for variables.
=−5+−5m/s(3.65s)
Compute range in z-direction.
=−23.25m
Write range(final position vector) using all components:
Final position = ⟨292,0,−23.255⟩m