In this situation the motives of the defendant and the reasonableness of their conduct are the factors used to determine the unreasonableness of their actions. This is one of the few exceptions to the rule that malice is not relevant in tort law. In Christie v Davey, the defendant was deliberately creating a noise to frustrate the claimants; based on this, it was held that their actions were malicious, unreasonable, and amounted to a nuisance.
A fixed pulley has a mechanical advantage of one, however, it is able to change the direction of force on an object. A movable pulley has a mechanical advantage of two and is connected to the object being moved.A block and tackle pulley provides a mechanical advantage of three and is made up of fixed and movable pulleys. Calculating the mechanical advantage of a pulley:ith a pulley, the user pulls one end of the rope and the other end of the rope pulls up on the object you want to move. The force produced by the user of the pulley is called the input force and the force pulling up on the object is called the output force.
The advantage of the fixed pulley is that you do not have to pull or push the pulley up and down. The disadvantage is that you have to apply more effort than the load. A movable pulley is a pulley that moves with the load. The movable pulley allows the effort to be less than the weight of the load. The movable pulley also acts as a second class lever. The load is between the fulcrum and the effort. The main advantage of a movable pulley is that you use less effort to pull the load. The main disadvantage of a movable pulley is that you have to pull or push the pulley up or down. If you add a second pulley, the amount of effort to lift the heavy object is much less . For example, to lift a box weighing 150 N, one would need to exert 150 N of force without the help of pulleys. However, by using just two pulleys, the person would only need to use 50 N of force. A combined pulley makes life easier as the effort needed to lift the load is less than half the weight of the load. The main advantage of this pulley is that the amount of effort is less than half of the load.