Uniform Rectilinear Motion
This activity belongs to the GeoGebra book The Domain of the Time.
After creating a time register, we can place a point M (representing a mass m) and create a constant vector v. By the definition of velocity, the mass will move a distance dt v. Therefore, we simply need to add the following instruction to the script of the slider anima (according to Newton's first law):
SetValue(M, M + dt v)
This instruction ensures that M moves in a uniform rectilinear motion. Notice that this instruction only makes M shift "a little bit" (dt) in the direction of v every time the slider's value is updated.
button:
SetValue(M, P)
The uniform rectilinear motion is particularly important because, according to Newton's first law, any mass will remain at rest or continue moving in a straight line at a constant speed (with respect to a reference system) unless acted upon by a net external force. This means that the mass resists any change in its state of motion, a property known as inertia.
- Note: Since the time fraction dt is measured in seconds, the velocity v should be in m/s, and we will use meters as the unit on the axes.
button:
SetValue(M, P)
The uniform rectilinear motion is particularly important because, according to Newton's first law, any mass will remain at rest or continue moving in a straight line at a constant speed (with respect to a reference system) unless acted upon by a net external force. This means that the mass resists any change in its state of motion, a property known as inertia.SCRIPT FOR SLIDER anima
# Calculate the elapsed seconds dt; add one second if t1(1) < tt
SetValue(tt, t1(1))
SetValue(t1, First(GetTime(), 3))
SetValue(dt, (t1(1) < tt) + (t1(1) − tt)/1000)
# Move M
SetValue(M, M + dt v)
Author of the activity and GeoGebra construction: Rafael Losada.