Kiti Katsu

Today, I observed my cat make a round trip in the backyard. I saw my cat attempt to chase some birds that were hanging around in the yard. Starting her pursuit around her dinner drop-off area, she began her chase with a constant casual walk and then increased her speed until the birds flew away to a nearby house. As the birds flew, she slowed down until she reached a full stop to stare at the birds. Then, as she heard her dinner touch the ground, she ran back the way she came from by slowly increasing her speed until finally stopping at her food bowl to eat.

This experience reminded me of displacement, velocity, and acceleration. My cat's displacement at the end of her bird pursuit was about 15 meters, and along the way, she varied her velocity and acceleration. If the direction in which she moved as she chased the birds was positive, then she began with a positive velocity with no acceleration. As she sped up, she positively accelerated with a higher positive velocity. Then as she slowed down, she negatively accelerated but still had a lower positive velocity until she finally reached a stop.

Then as she changed direction toward her food, she negatively accelerated since she was speeding up in the backwards direction until she reached her food where she once again had 0 acceleration. During this time, she had increasingly negative velocity since she was speeding up in the backwards direction until reaching her stop of 0 velocity. Her total displacement of the whole trip was 0, but her total distance traveled was about 30 meters.