How Is Upward Force Calculated in a Lever System?

[Liamsbab]

Homework Statement

The thigh muscle that bends the knee is attached to the bone 2cm away from the fulcrum and generates a force of 400N. The distance between the weight and the fulcrum is 40cm. Calculate the upward force at the point where the muscle in the thigh contracts.

Homework Equations

No idea, i am really confused.

The Attempt at a Solution

None

 

[berkeman]

What can you tell us about torques? Can you sketch a diagram showing the problem statement, and label the forces, where they act, and how they make torques?

 

[Moetasim]

, due to lack of understanding of the problem.

I can understand how this problem can be confusing. Let's break it down step by step.

First, we need to identify the key information given in the problem. We are told that there is a thigh muscle that bends the knee and it is attached to a bone 2cm away from the fulcrum. The muscle generates a force of 400N. We are also given the distance between the weight and the fulcrum, which is 40cm.

Next, we need to understand the concept of a lever and how it works. A lever is a simple machine that consists of a fulcrum (pivot point), a load (resistance), and an effort (force). In this problem, the thigh muscle is the effort, the weight is the load, and the fulcrum is the point of rotation.

Now, we can use the equation for calculating the mechanical advantage of a lever:
MA = distance from fulcrum to effort / distance from fulcrum to load

In this case, the distance from the fulcrum to the effort (thigh muscle) is 2cm and the distance from the fulcrum to the load (weight) is 40cm. Plugging these values into the equation, we get:
MA = 2cm / 40cm = 0.05

This means that for every 0.05cm the thigh muscle contracts, the weight will move 1cm.

To calculate the upward force at the point where the muscle contracts, we can use the equation:
Force = load x MA

In this problem, the load is 400N and the MA is 0.05. Plugging these values into the equation, we get:
Force = 400N x 0.05 = 20N

Therefore, the upward force at the point where the muscle contracts is 20N.

I hope this explanation helps to clarify the problem and guide you towards solving it. Remember to always identify the key information and use the appropriate equations to solve the problem.