Solving v(t)=0 for a particle gives t=−2 s and t=5 s. If the motion is being studied only from t=0 onward, when does the particle come to rest?
Physics · Mathematical tools and vector · Quadratic Equation
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Question

Solving v(t)=0 for a particle gives t=−2 s and t=5 s. If the motion is being studied only from t=0 onward, when does the particle come to rest?

G1 Physics · Accepted Answer

Both values are mathematical roots, but the model is being used only for t≥0. Therefore t=−2 s lies outside the physical time domain. The admissible time is t=5 s.