Physics

Problem

An object of mass

3\,\text{kg}

moves in a plane such that its position vector at time

t

\mathbf r = (2t^{3}\,\hat i + 5t^{2}\,\hat j)\,\text{m}

. a. Obtain an expression for the instantaneous force acting on the object as a function of time. b. Find the force at

t = 1\,\text{s}