Hey , im not really the most brightest student when it comes to physics and i really dont understand it at all . but we are doing a prac in class and here it is Theory: A Clamped metal strip has a natural frequency of vibration which is related to its length. The shorter the leng, L the higher is its natural frequency. Apparatus: The metal strip you will use is part of an old ticker timer. This has an electromagnet in front of the clamp and a permanent magnet. When the electromegnet is connected to 4 Volt AC ( yellow terminals on power pack ) the metal strip is set vibrating at 50 Hz , Your task is to vary the length of the metal strip by shifting it in the clamp so that you acn adjust its natrual frequency to near 50 Hz. To make the results more clear you will take measurements of amplitude of vibration to near 50 Hz. To make the results more clear you will measurements of amplitude for different lengths. You will vary its length so that its natural freuqency varies either side of 50Hz . thats what we're doing . can someone please help me with the results and whats going on in this prac ? so that i can understand what we're doing first then i can write up this prac. thank you. If anyone needs more info on the prac just ask and ill write up the procedure.