# Problem Newtonian mechanics French

• leoleo
In summary, the conversation discusses a prisoner's attempt to escape jail using a rope provided by an accomplice. The rope has a mass of 10 kg and the prisoner has a mass of 70 kg. The hook outside the prisoner's window can withstand a maximum force of 600 N. The question asks for the minimum velocity needed for the prisoner to reach the ground from a window 15 m above the ground, starting from rest at the top of the rope. The solution involves calculating the maximum force on the hook, using two free body diagrams, and finding the velocity using the formula v=SQRT(2*a*h). However, the lack of definition for T makes it impossible to fully solve the problem.
leoleo
Member advised to use the homework template for posts in the homework sections of PF.
A prisoner in jail decides to escape by sliding to freedom down a rope provided by an
accomplice. He attaches the top end of the rope to a hook outside his window; the
bottom end of the rope hangs clear of the ground. The rope has a mass of 10 kg, and the
prisoner has a mass of 70 kg. The hook can stand a pull of 600 N without giving way. If
the prisoner's window is 15 m above the ground, what is the least velocity with which he
can reach the ground, starting from rest at the top end of the rope?

My solution:

For the hook I calculate:

M-mass rope 10 kg

m-mass prisoner 70 kg

F –force max. on the hook 600 N

h-height 15 m

(1) F>T+Mg

(2) ma=mg-T

From 1 T < F-M and from 2 mg-ma<F-Mg

Ma>(m+M)*g-F

a>((m+M)*g-F)/M

Now v=SQRT(2*a*h) I can find h.

But I am not sure for two free body diagram : (1) and (2). Is (1) probably F>T+Mg+mg because prisoner is on the rope or in (2) there is influence of mass of rope or not on the prisoner?

Please help how to think at this problems.

Now v=SQRT(2*a*h) I can find h.

It should be: I can find v

leoleo said:
Is (1) probably F>T+Mg+mg
It is impossible to answer your question since you have not defined T.

## 1. What is Newtonian mechanics?

Newtonian mechanics, also known as classical mechanics, is a branch of physics that describes the motion of objects under the influence of forces. It was developed by Sir Isaac Newton in the 17th century and is based on his three laws of motion.

## 2. What are the key principles of Newtonian mechanics?

The key principles of Newtonian mechanics include the first law of motion (an object at rest will remain at rest and an object in motion will remain in motion unless acted upon by an external force), the second law of motion (force equals mass times acceleration), and the third law of motion (for every action, there is an equal and opposite reaction).

## 3. How is Newtonian mechanics related to French scientists?

Although Sir Isaac Newton was British, his work on Newtonian mechanics was heavily influenced by the work of French scientists such as René Descartes and Galileo Galilei. Additionally, French scientists such as Pierre-Simon Laplace and Joseph-Louis Lagrange made significant contributions to the development of Newtonian mechanics.

## 4. What are some real-world applications of Newtonian mechanics?

Newtonian mechanics is used to explain the motion of objects on Earth and in space, and it is the basis for many engineering and technological advancements. Some examples of real-world applications include the design of bridges and buildings, the study of planetary motion, and the development of transportation systems like cars and airplanes.

## 5. Are there any limitations to Newtonian mechanics?

While Newtonian mechanics is incredibly accurate in most situations, it does have some limitations. It does not fully explain the behavior of objects at very high speeds or in very small scales (such as atoms and particles). In these cases, more advanced theories like Einstein's theory of relativity and quantum mechanics are needed.

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