You need to design an experiment to measure the free-fall acceleration. you have an inclined plane made of steel and several objects that you may place on the plane. the plane is fixed at 45°. you have a teflon-coated block with a mass of 0.5 kg, a cart with steel wheels and a mass of 1.5 kg, and a steel box with a mass of 0.75 kg. you have a sonar device to measure the acceleration. you are to place one or more objects on the plane and measure their acceleration along the plane. does it matter which object or objects you choose? if not, why not? if so, which would you use? explain your answer.