# Question Video: Determining the Magnitude of the Displacement Vector Based on Time and the Expression of the Position Vector Mathematics • Second Year of Secondary School

A particle moving in a straight line has a position vector 𝐫, defined by the relation 𝐫 = (𝑡² + 3)𝐧, where 𝑡 is the time measured in seconds and 𝐧 is a unit vector. Determine the magnitude of the displacement vector 𝐬 in meters after 4 seconds