Further

1. Show that one N•m is equal to one J.

2. Start with a stretched spring and let the spring do work on the cart by accelerating it toward the fixed point. Use the Motion Detector to determine the speed of the cart when the spring reaches the relaxed position. Calculate the kinetic energy of the cart at this point and compare it to the work measured in Part II. Discuss the results.

3. Repeat constant force experiment, but vary the speed of your hand as you lift the mass. The force vs. time graph should be irregular. Will the force vs. distance graph change? Or will it continue to correspond to mg·Δh?

4. Repeat cart experiment, but start with the cart moving away from the detector. Pushing only with the tip of the Force Sensor, gently stop the cart and send it back toward the detector. Compare the work done on the cart to the change in kinetic energy, taking into account the initial velocity of the cart.