Question

A galactic police officer's hovercraft is parked at a speed trap when a speeder bike flies past at 68.0 m/s. It takes the officer 2.00 s to react and get his hovercraft started. He then takes off after the speeder bike with a constant acceleration of 4.00 m/s^2. Consider time t = 0 to be when the officer's hovercraft begins to move, and consider position x = 0 to be the location of the speed trap. With these choices, identify the following three pieces on information for each vehicle. How far from the speed trap will they be when the officer catches up? What is the maximum distance ahead of the officer the speeder bike will get before the officer starts to close the gap?

Answer 1

Initial velocity of hovercraft = vih= 0 m/s ……(It’s correct)

Initial position of speederbike = x0s = 68*2 = 136 m

a) xfh = xfs

x0h+vih*t +1/2*ah*t^2 = x0s+vis*t

0+0*t -1/2*4*t^2 = 136+86*t   => t= 35.9s

xfh=xfs = 2577.2m

b) The maximum distance = 68.0*2.0 = 136 m