Tommy was walking at a rate of 4 miles/hour at noon and at 12:30 pm he was walking at a brisk rate of 6 miles/hour.Two hours later Tommy was walking at a leisurely rate of 2 miles/hour. Which statement about Tommy's accleration is true?
I think Tommy had a positive acceleration between noon and 12:30 pm, That is the acceleration was (6-4)/1/2 = 4 miles/ square hour. However between 12:30 pm to 2:30 pm Tommy had a negative acceleration.