Differentiate between the arrangement of elements (load, fulcrum, and effort) in first-, second-, and third-class levers.

Question

Accepted Answer

Hi, everyone. Let's take a look at this practice problem together in the bicep curl exercise, which parts act as the fulcrum, the effort and the load. The answer options are a, the bicep muscle acts as the fulcrum. The elbow joint applies the effort and the weight being lifted is the load b, the elbow joint acts as the fulcrum. The weight being lifted is the effort and the bicep muscle is the load c the elbow joint axes, the fulcrum, the bicep muscle applies the effort and the weight being lifted is the load and option D, none of these. So for this answer, we need to match the three parts of the bicep curl exercise with the three parts of the lever. So for the bicep curl, the three parts are the bicep muscle, the elbow joint and the weight and the three parts of the lever, as stated in the question, are the fulcrum, the effort and the load. So, recall in a lever, the fulcrum doesn't move. So out of the bicep curl exercise components or options, which part does not move, it's the elbow joint. So that means that the elbow joint is the Fulcrum and we can eliminate option A because option a incorrectly states that the bicep muscle is the full ground. Now, in lovers recall that there is effort and effort is the input force or it's the applied force and the load is the output force. It's the part of the lever that needs to and will be moved. So the load moves. Now in a bicep curl, the effort is going to be what the bicep muscle or the weight. So the effort is going to be the bicep muscle while the weight is the load. So it's the weight that will eventually move. So we've correctly paired, the elbow joint is the fulcrum. The bicep muscle is the effort and the weight is the load. So the answer option that correctly states this is option c the elbow joint acts as the fulcrum. The bicep muscle applies the effort and the weight being lifted is the load. The correct answer is option C, all right, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.

Differentiate between the arrangement of elements (load, fulcrum, and effort) in first-, second-, and third-class levers.

Verified Solution

Key Concepts

First-Class Lever

Second-Class Lever

Third-Class Lever