A particle moves in one dimension, and its position as a function of time is given by

x= (2.3m/s)t+ (2.8m/s²)t².

(a) What is the particle's average velocity fromt= 0.45 s tot= 0.55 s? (Indicate the direction with the sign of your answer.) m/s (b) What is the particle's average velocity fromt= 0.49 s tot= 0.51 s? (Indicate the direction with the sign of your answer.) m/s