Answer:
Now that you know how forces affect the motions of objects, you can use the Tracker video analysis tool to create dynamic models
for a wide range of physical situations.
Tracker enables you to create two different types of mathematical models: analytical and dynamic. An analytical model enables you
to enter mathematical expressions for x and y positions as a function of time. That's sometimes useful, but from a physics
perspective, a dynamic model is much more flexible and powerful.
A dynamic model enables you to set the initial conditions for a particular system (Initial positions and velocities); then you can
mathematically define any forces acting on that system. Once those are set up, the model acts like an object in space, responding to
the forces you've imposed on it. It can continue moving forever, if that's what the forces would do to an object in real life. By visually
matching a marker for your model to the real motion on the video, you can define and refine a mathematical model for a
Acceleration I think if I’m not mistaken
The speed is changing its direction all the time. There
is an acceleration which changes the direction of the speed – that is called
centripetal acceleration. Only uniform linear motions are considered to have no
acceleration.
This is the general formula for acceleration
a = dv/dt
When calculating dv, you should keep in mind the change
in the velocity vector’s direction. You can easily see in a graph that with dt
tending to 0 (so the length of the arc covered is also tending to 0), the difference
between vectors Vf and V0 has a direction which is perpendicular to velocity
(the shorter the arc, the closest the angle is to 90 degrees).
There is a formula (which can be deducted from the
previous formula) which allows you to calculate the acceleration:
a = v^2/r
Let’s talk about the units:
v is in m/s
r is in m
so v^2/r
is in (m/s)^2/m = (m^2/s^2)/m = m/s^2
which is the same unit as dv/dt:
dv/dt = (m/s)/s= m/s^2
