Physics Lab Experiment Wikispaces（物理实验室实验Wikispaces）.docVIP

Physics Lab Experiment Unit 2: Conservation Laws Inquiry Lab: Roller Coaster Learning goals: Evaluate the law of conservation of energy. Plan a procedure for collection of data Analyzing data to confirm a conservation law and observe the effect of a non-conservative force. Purpose: To evaluate the law of conservation of energy for a roller coaster. Pre-lab Activity: 1. Read the complete lab. Make note of any section that is confusing and write your questions below. 2. The following data are obtained for a cart rolling down a ramp. Calculate the total mechanical energy (PE+KE) at the start and at the end. Is the total mechanical energy present at the start conserved (that is, does the PEgravity + KE stay constant)? If not, how much energy is lost? Cart at top of ramp Mass = 1.5kg; Height = 1.8m; Speed = 0m/s Cart at bottom of ramp Mass = 1.5kg; Height = 1.0m; Speed = 4m/s 3. The following data are obtained for a cart rolling down a ramp. Calculate the total mechanical energy (PE+KE) at the start and at the end. Is the total mechanical energy present at the start conserved (that is, does the PEgravity + KE stay constant)? If not, how much energy is lost? Cart at top of ramp Mass = 0.75 kg; Height = 2.2m; Speed = 1m/s Cart at bottom of ramp Mass = 0.75 kg; Height = 1.3m; Speed = 2.8m/s 4. What are some other forms of energy that may be relevant to the roller coaster? If we observe the total mechanical energy to increase (or decrease), where might that energy come from (go to)? Statement of Problem We have discussed the law of conservation of energy which states: Energy cannot be created or destroyed. Energy may be converted from one form to another. Your goal is to use the law of conservation of energy to account for the behavior of a toy roller coaster. In order to do this, you will need to examine the mechanical energy (the KE and PEgravity) of the cart and explain any increase or decrease. One way that mechanical energy is changed is