Question

4) One of your fellow classmates wonders how Newton’s Third Law works in a case for a pickup truck towing a recreational vehicle (RV) to Beaver Stadium. “After all,” in this student’s words, “if they start from rest and the RV pulls back on the truck with the same size force as the truck pulls on the RV, shouldn’t the acceleration of the system be zero?” What is your response to this student(in words, don’t write any equations)? (Something to think about is to consider what object exerts the external forces here; what is that object’s acceleration?)

Answer 1

The acceleration would not be zero as there is an engine that is exerting external force on the truck+RV system ,and since the engine is exerting a non zero force therefore net force on the system is not zero and acceleration is also non zero