- Measure the position of the red truck at two different times. Use the position of the front tire as the position of the truck. Use this information to calculate the initial position and velocity of of the truck.
- Figure out how far behind the truck the trailer needs to be. Measure the distance from the front tire to the center of the towing tongue of the truck. Then measure the distance from the center of the towing tongue of the trailer to the wheel. The total distance is how far behind the truck the trailer needs to be.
- Using the equation of motion for the truck and the trailer, write the equation of motion for the trailer in the box below. Your equation will look something the one below, except
*x*and*v*will be replaced by numbers. (Since this is a function of time, "t" must appear in the expression.)

Then click on the button to make the trailer follow your equation of motion. If the two vehicals do not move together so that the hookups match exactly, check you calculations.*x*+*v**t

Exercise created by Scott Bonham, Western Kentucky University.

Physlet by Wolfgang Christian, Davidson College