PHY 2020 Chapter Notes - Chapter 3: Motorboat, Free Fall, Odometer
Document Summary
Checkpoint 1: a hungry mosquito sees you resting in a hammock in a 3-m/s breeze. Galileo is credited with being the first to measure speed by considering the distance covered and the time it takes. Galileo could easily measure distance, but in his day measuring short times was no easy matter. Since average speed is the distance traveled divided by the total time of travel, it does(cid:374)"t i(cid:374)di(cid:272)ate the differe(cid:374)t speeds a(cid:374)d (cid:448)ariatio(cid:374)s that (cid:373)ay ha(cid:448)e take(cid:374) pla(cid:272)e duri(cid:374)g shorter time intervals. If we know average speed and time of travel. A simple rearrangement of our definition gives: total distance covered=average speed *time interval. Velocity: combines the idea of speed and direction of motion. Vector quantity: quantity such as velocity that specifies direction as well as magnitude. Scalar quantity: a quantity that requires only magnitude: speed is scalar quantity. Constant velocity: both constant speed and constant direction.
