b) i) State the principle of moments. ii) Determine the value of X, assuming that the beam is balanced. iii) Calculate the reaction force acting at the pivot, given that the beam is balanced.

Here are the solutions to your questions: 2.b) i) State the principle of moments. The principle of moments states that for an object to be in equilibrium, the sum of the clockwise moments about any point must be equal to the sum of the anticlockwise moments about the same point. ii) Determine the value of X, assuming that the beam is balanced. Assumption: The block shown at 2m from the pivot does not exert a significant downward force or its weight is negligible for the purpose of calculating moments. Step 1: Identify clockwise and anticlockwise moments about the pivot. Anticlockwise moment = Force × Perpendicular distance from pivot Anticlockwise moment = 30 N × 3 m = 90 Nm Clockwise moment = Force × Perpendicular distance from pivot Clockwise moment = X N × 3 m Step 2: Apply the principle of moments (Clockwise moment = Anticlockwise moment). X × 3 m = 90 Nm X = 90 Nm3 m X = 30 N The value of X is 30 N. iii) Calculate the reaction force acting at the pivot, given that the beam is balanced. Assumption: Only the labeled forces (30 N and X N) contribute to the downward forces. The weight of the beam acts at the pivot and thus does not contribute to the net vertical force for equilibrium calculation, and the block's weight is negligible. Step 1: For vertical equilibrium, the sum of upward forces equals the sum of downward forces. Upward force = Reaction force (R) at the pivot. Downward forces = 30 N + X N Step 2: Calculate the reaction force. R = 30 N + 30 N R = 60 N The reaction force acting at the pivot is 60 N. 2.c) State one difference between mass and weight. Mass is a measure of the amount of matter in an object, while weight is the gravitational force acting on an object. Mass is constant regardless of location, whereas weight varies depending on the gravitational field strength. 3.a) i) Explain what happens if a device that draws 8A is used. If a device that draws 8 A is used with a fuse rated at 5 A, the current will exceed the fuse's rating. The fuse wire will melt due to the excessive heat generated by the high current, breaking the circuit and protecting the device and wiring from damage. ii) Why are household circuits wired in parallel instead of series? Household circuits are wired in parallel so that each appliance receives the full supply voltage, allowing them to operate at their intended power. Additionally, if one appliance fails or is switched off, the other appliances in the circuit can continue to function independently. 3.b) i) Consider when the key, K, is open. What will be the ammeter reading? When the key K is open, the circuit is incomplete, meaning no current can flow through it.