A particle moves along the x-axis according to x (t) = 18t - Give your answers to two significant figures. (a) What is the instantaneous velocity at t = 2 s and t = 3 s? -3t m. The instantaneous velocity at t = 2 s is 12 m/s. The instantaneous velocity at t = 3 s is 6.0 m/s. (b) What is the instantaneous speed at these times? The instantaneous speed at t = 2 s is Number m/s. The instantaneous speed at t = 3 s is Number m/s. (c) What is the average velocity between t = 2 s and t = 3 s? The average velocity between t=2s and t = 3 s is x = Number m/s.