Hi everyone. I am self studying for my GCE for the past 6 months now. I have been doing revision for a long time and did some question papers. I have a few problems and hope the people here can guide me. Thank you Problem 1. 1. The problem statement, all variables and given/known data A 5.0kg mass is suspended from the ceiling. A horizontal force F is applied to hold the string in position as shown http://i.imgur.com/ZdR72ff.jpg Determine the reading of F on the spring balance by using a scale diagram 2. Relevant equations None 3. The attempt at a solution http://i.imgur.com/2KO2AnT.jpg Am I doing it correctly? It doesn't really make sense to me. I can't determine the force F. I only have 30degree angle and the weight. Problem 2 1. The problem statement, all variables and given/known data A ladder weighing 200N is being held by a man. The man shoulder acts as a pivot. His arm is pushing an upward force F. http://i.imgur.com/dMrcRtK.jpg Where could a weight of 150N be hang upon, so that force F do not need to counteract the weight of the ladder 2. Relevant equations Moment= F x Perpendicular Distance 3. The attempt at a solution I am not sure if I am understanding it correctly. If I am not wrong, the question is asking me, where can I hang a weight of 150N, so that force F no need to counteract the weight of the ladder. Meaning, assume force F = 0N. Let the distance be x Total clockwise moment = total anti clockwise moment 150x = 200*0.5 150x = 100 x = 2/3 = 0.667m. Therefore it needs to be hang 0.667m away from the pivot or at 3.167m of the ladder. Am I understanding this correctly? Problem 3 1. The problem statement, all variables and given/known data The figure shows 2 terminals M and N of a potential divider connected to a 6V battery. The circuit is connected to a Cathode-ray Oscillator. http://i.imgur.com/zeV2e3j.jpg (a) Describe in details what happens as the terminal is moved at a uniform speed from N to M. (b) Draw the final reading of the final trace that is shown the CRO as N is moving towards M. 2. Relevant equations None 3. The attempt at a solution (a) As terminal N is moving towards M, there will be an increased in e.m.f, the results in a higher reading on the tracd (b) http://i.imgur.com/bldLWjF.jpg This is my attempt. Please correct me if I make any mistakes thank you. Theoretical Problem: Is the work done the same if I move an object vertically upwards of height 2.0m v.s moving up a ramp at height until it reaches 2.0m? From what I memorise, they are the same. Am I right? But can someone explain why? I want to understand why. Thank you!