Playing with my Dog

Earlier today at home, my dog ran up to me with her toy in her mouth. I took the doll from her, tossed it, and watched her go after it. Her action reminded me of something I learned in physics. If I was the origin and tossed the doll, my dog would be running forward with a positive acceleration. When she slows down to grab the doll, her acceleration becomes negative. When she turns around and runs back toward me she has a positive acceleration but a negative velocity. This is because she turns around and is running back toward me, the origin. Once she reaches me and stops, the total displacement is zero because her initial starting spot was where she ended.

So if I was to graph her running, the position graph would look like a short steep slope when she is running toward the doll then a gradual one when she grabs it. Then it would gradually go down then become steep once she picks up speed back toward me. The velocity graph would be a gradual hill going up then drop back to zero once she reaches the doll then it would become a negative slope as she runs back toward me. The acceleration graph would go from zero to positive when she is speeding up toward the doll, then negative to positive when she slows down to grab the doll and then speeds up toward me, and finally negative to zero as she slows down to a stop where I am.