Question

Part 4: Write complete, thoughtful answers the to the following questions.

Question 1: What is the relationship between the number of pulleys and the force required to lift the mass?

Question 2: What is the relationship between force required to lift the mass and the length of the rope?

Question 3: Explain the difference (in your words) the difference between Ideal and Actual Mechanical Advantage.

Describe your understanding of the three simple machines that we reviewed in class

Answer 1

Question 1 :What is the relationship between the number of pulleys and the force required to lift the mass?

Answer: As we are very well aware that they pully helps us to lift the weigth or mass by allowing us to change the force direction apllied on it .The relation of force and number of pulley is that , If we increase the number of pulleys , the effort or force applied is reduced but the same time the cost of pulling the rope over a greater distance .we can understand it by an example suppose that there are 3 pulleys seperately and same mass attached to pulley ends . we will realize by this that lesser force is required in doing the work comparing to the signle pulley with attached mass . It depends up on the number of parts of ropes supporting the load , the direction in whihc the force is applied and whether the pulley is fixed or movable pulley system

Question 2: What is the relationship between force required to lift the mass and the length of the rope?

Answer As we saw in above answer that how the number of pulleys lessen the effort or input force required to lift a mass or weight . but It is also same the case of rope which connects the pulley and the Mass. Increase in the number of pulley will also increase the length of the rope that will ultmately lesses the required input force .

Suppose If an object we want to lift by a rope , its weight (w) will act downward ( obviously ) .Now this downward force will cause a tension in the rope whihc will act in the upward direction and is same all along the rope . Also let us say that there are A number of parts of the rope that are supporting the object or load . w , then the tensin in each part will be w/A . therefore it is clear from this that the input force is w/A that it is reduced by a factor A. This is the relation between the lenght of rope and the force required to lift a mass

Question 3: Explain the difference (in your words) the difference between Ideal and Actual Mechanical Advantage.

Answer The Mechanical Advantage is the representation ratio of how much work is done with the given input or we can say that if a force F applied how much it do its work i-e output . In case of Ideal Mechanical Advantage , we have some assumption theoretically for example Frictional force , Air resistance , etc .which we consider negligible . .

Ideal mechanical advantage is given by IMA = Distance Of Effort/ DistanceOfLoad(OrResistance)

Ideal mechanical advantage (IMA) mathematically defined as the ratio of distance of the effort over distance of the load force. If the distance of the effort (where you apply the force) force is greater than the distance of the load force ( where the object being moved is located relative to the mass), the IMA will be greater than one, and vce versa. An IMA greater than 1 means that (in a frictionless world) the system will require a force that is less than the load in order to mive it, but the effort will have to move a higher distance. while , an Ideal MA less than 1 means that the effort force must be greater than the force of the load in order to move it, but less distance is required of the effort to move the load a higher distance.

While In case of Actual Mechanical Advantage it is a measuring based MA which means that we need to measure the force or effort over a distance using tools and instrument to actually find the Mechanical Advantage . In Acutal Mechanical Advantage , It takes into account the frictional losses, energy , deflection , wear , etc unlike the Ideal Mechanical Advantage .

I Hope that you may now fully understand the concepts of Pulleys, forces,rope and Mechanical advantage and how it varies with their parameters .

have a Good day