Greetings all I'm new to this forum, so please spare me if I make a fool of myself in this post. I was working on a Physics Practical this morning at school concerning Change in Mechanical Energy, in relation to Potential and Kinetic Energy. Although it seems like a easy task, I'm getting confused by all the calculations. Outline of the prac: We had a wooden board about 1.79 metres in length and we had to slide a wooden block (232.3 grams) from the top of the board to the bottom, measuring the time it took to slide from the top to the bottom. We repeated the same steps but with the wooden board placed at varying heights. (E.g. 0.7m, 0.85m, 1m, 1.15m, 1.30m), therefore also at different angles (which I've managed to calculate already). Then by using our results (the time it took for the block to reach the ground for each height) we have to calculate the Change in Mechnical Energy. There are several different ways to calculate ME, and I'm confused about which one is actually the correct procedure. If anyone has the time to give me some suggestions, it would be greatly appreciated. The formula for Mechanical Energy is: ME = (1/2)mv^2 + mgh (ME = Kinetic Energy + Potential Energy), but what numbers do I use to work out KE and PE? Thanks.