A woman swimming upstream is not moving with respect to the shore. Is she doing any work? If she stops swimming and merely floats, is work done on her?
Chapter 2: Motion in One Dimension 2.1 Describing Motion distance = scalar , displacement = vector = Δx (orΔy ) ‘trajectory’ When she goes Position vs time x vs t): slope = velocity backwards, the slope and velocity are negative. speed = scalar , velocity = vector v = Δx v = Δy x Δt y Δt 2.2 Uniform Motion constant velocity ! no speed-up or slow-down AND no change in direction!! € € Δx = v xt , or x – x0= v xt – t 0 , which we usually write as x = vxt , taking initial time and position