Principle of Transmissibility of Forces Worksheet

A car is being pulled by a force applied through a rope. According to the principle of transmissibility of forces, explain how the force can be applied at different points along the rope without changing the effect on the car. Use reasoning to justify your answer.

• The force can be applied at any point along the rope’s line of action, and the effect on the car will remain the same if the magnitude and direction are unchanged.

• The force must always be applied at the front of the car to move it.

• The force will only work if applied at the midpoint of the rope.

• The force changes direction if applied at different points along the rope.

A person is holding a 20 kg fence post above the ground using a cable that makes a 15° angle with the horizontal. Using principles of equilibrium, how would you determine the tension in the cable and the reaction at the ground?

• By resolving forces and moments acting on the post and applying the conditions for static equilibrium.

• By measuring the length of the cable and the height of the post.

• By calculating the area of the ground in contact with the post.

• By estimating the force visually from the diagram.

Determine the force in the hydraulic cylinder and the reaction at the support pin for the engine crane when it has a 1200 N load on it. Explain your reasoning and the steps you would take to solve this problem, including any assumptions you would make about the system.

• Use the principles of static equilibrium to set up equations for forces and moments, solve for the unknowns, and assume the crane is a rigid body.

• Guess the values based on similar problems without calculations.

• Ignore the angle of the hydraulic cylinder and only consider the vertical forces.

• Assume the load is distributed evenly along the crane arm.

Given the diagram of an engine crane with a 1200 N load applied vertically downward at the end of the beam, and a hydraulic cylinder positioned at a 30° angle, how would you determine the force in the hydraulic cylinder and the reaction at the support pin? Select the best approach that demonstrates strategic reasoning and planning.

• Use the method of joints to analyze the forces, considering the equilibrium of the entire structure and resolving forces at the pin and along the hydraulic cylinder.

• Assume the hydraulic cylinder force is equal to the load and ignore the angle of application.

• Only consider the vertical components of the forces and ignore the horizontal components.

• Use the Pythagorean theorem to directly calculate the force in the hydraulic cylinder without considering moments.

A student is using a pair of scissors to cut a piece of paper. Explain how the principle of mechanical advantage applies in this scenario, and describe how the distance and effort are related to the work being done.

• The scissors allow a small force applied over a larger distance to cut the paper, demonstrating mechanical advantage; the longer the handles, the less effort needed for the same work.

• The scissors require more force as the handles get longer, making the work harder.

• The scissors do not provide any mechanical advantage, and the effort is unrelated to the distance.

• The scissors only work because of sharpness, not because of any mechanical principle.

A student is given three different types of levers (1st class, 2nd class, and 3rd class) and asked to determine which configuration would provide the greatest mechanical advantage if the effort arm is much longer than the load arm. Using your understanding of lever classes and the formula for mechanical advantage, which lever class would you recommend and why?

• 1st class lever, because the effort arm can be made much longer than the load arm, maximizing MA.

• 2nd class lever, because the load is always between the fulcrum and effort, regardless of arm lengths.

• 3rd class lever, because the effort is always between the fulcrum and load, maximizing MA.

• All lever classes provide the same mechanical advantage if the arms are equal.

A student is given a scenario where they need to lift a heavy load using minimal effort. They have access to a second-class lever, such as a wheelbarrow. Explain how the mechanical advantage of the lever helps them achieve this task, and predict what would happen if they used a third-class lever instead.

• The second-class lever amplifies the force, allowing a small effort to lift a heavy load, while a third-class lever would require more effort to lift the same load.

• The second-class lever increases speed and range, while a third-class lever amplifies force.

• Both levers provide the same mechanical advantage, so the effort required is the same.

• The third-class lever is always more efficient than the second-class lever for lifting heavy loads.

A group of students is tasked with predicting the efficiency of a lever system. They are asked to analyze the forces acting on the lever. What reasoning process should they use to calculate the mechanical advantage and predict the system's efficiency?

• They should identify the input and output forces, calculate the ratio, and use this to determine the mechanical advantage and efficiency.

• They should only measure the length of the lever.

• They should ignore the forces and focus on the material of the lever.

• They should assume all levers have the same efficiency regardless of forces.

A company is designing a new lever system for lifting heavy objects in a factory. Explain how understanding both the effort force (input force) and the load force (output force) can help engineers ensure the system is both safe and efficient. What should they consider when planning the amount of force to apply?

• They should only focus on maximizing the load force, ignoring the input force.

• They should ensure the input force is as high as possible to guarantee movement.

• They should balance the input and output forces to apply just enough force to move the load without causing damage or inefficiency.

• They should minimize both forces to reduce energy use, regardless of whether the load moves.

Imagine you are tasked with designing a lever for a piece of machinery that must lift fragile objects. How would you use your understanding of input and output forces to prevent damage to the objects while maintaining efficiency?

• Apply the maximum possible input force to ensure the object is lifted quickly.

• Carefully calculate the required input force so that the output force is just enough to lift the object without causing damage.

• Ignore the relationship between input and output forces and focus on speed.

• Use trial and error to determine the force needed, regardless of efficiency.