Question

A child operates a remote controlled toy car on a linear track. The figure below plots the car's position as a function of time. x (m) Find the velocity of the toy car at the following times. Indicate the direction with the sign of your answer. (a) t 1.4 s: 1.4 Remember that velocity is the change in position per the change in time. If the graph plots position vs. time, what property of the plot in each segment is related to velocity? Think about the initial and final times and positions for each segment. m/s (b) t 3.2 s: 2.5 Remember that velocity is the change in position per the change in time. If the graph plots position vs. time, what property of the plot in each segment is related to velocity? Think about the initial and final times and positions for each segment. m/s (c) t 5.7 s: m/s (d) t 7.7 s: m/s

Answer 1

(a) From t = 0 to t = 2 the velocity is constant v = delta x/delta t (slope of the graph) v = 3 - 0/2 - 0 = 3/2 = 1.5 m's v = 1.5 m's t = 1.4 s (b) From t = 2 to t = 4s the velocity is constant v = delta x/delta t (slope of the line between t = 2 and t = 4b) v = -0.3 - 3/4 - 2 = -3.5/2 = -1.75 m's v = -1.75 m's t = 3.2 s (c) Between t = 4s and t = 6s velocity = 0 since slope of the line is 0 (d) Between t = 6s and t = 9s v = 0 - (0.5)/9 - 9 = 0.5/3 = 1/6 m/s (slope of line) v = 1/6 m/s t = 7.7 s