2 of 3 The position of a particle is described by r=(300e ^−0.5t)mm and θ=(0.3t ^2 )rad, where t is in seconds. Part A Determine the magnitude of the particle's velocity at the instant t=1.5 s. Express your answer to three significant figures and include the appropriate units. Determine the magnitude of the particle's acceleration at the instant t=1.5 Express your answer to three significant figures and include the appropriate units.