The discussion centers on the concept of external forces and their relationship to speed and velocity, specifically in the context of Newton's 1st Law of Motion. It is established that an object can maintain constant speed while experiencing a net external force, as demonstrated by a car traveling in a circular path. The key distinction between speed and velocity is emphasized, with velocity incorporating both magnitude and direction. The centripetal force acting on the car is identified as the net external force required to maintain this motion.
PREREQUISITESStudents of physics, educators teaching mechanics, and anyone interested in the principles of motion and forces in dynamics.
Good. Note the key word velocity. How does that differ from speed?crysland said:
Exactly! So see if you can try to answer the question now.crysland said:
How about a car following any curved path while moving at constant speed? A section of road could be similar to a sine wave, ellipse, spiral, parabola, ..., and a car would be able to follow that path while moving at constant speed.crysland said:
Your answer is definitely correct!crysland said:
Do you remember the expression for centripetal acceleration?crysland said:
That would be speed^2 / (radius of curvature), which gets complicated for paths other than a circle.arildno said:
The simple answer is that centripetal force = centripetal acceleration x mass of the car.crysland said: