# What are the reaction forces to the external forces on the wagon in (b)?

• Morrissey
In summary, the conversation discusses the identification of reaction forces exerted on objects enclosed in a dashed box. The question is whether the wagon exerts a force upwards to the left on the handle, and the options given do not include this choice. The second part of the conversation discusses the maximum friction force when one object is at rest and the driving force of another object. The recommendation is to post the second exercise in a separate thread.
Morrissey

## Homework Statement

One or more external forces are exerted on each object enclosed in a dashed box shown in the figures below. Identify the reaction to each of these forces, assuming that (b) occurs on Earth. Select all that apply.

(b) the wagon exerts a force

· downward on the Earth due to contact
· downward on the Earth due to gravitational attraction
· upward on the Earth due to gravitational attraction
· upward to the left on the handle (?)
· upward on the Earth due to contact

(My choices in underline)
3. The Attempt at a Solution

The main question I have about this problem is whether the wagon exerts a force upwards to the left on the handle. I thought that the wagon would exert a force downwards to the left on the handle, but this isn't an answer choice, so I thought that selection would be a trick question.

Last edited by a moderator:
Hi Morrissey,

(better to keep one exercise per thread -- less confusing)

Thread 2: when ##m_1## is at rest, the maximum friction force is ##\mu_s N = \mu_s m_1 g##; you must first check if the driving force ##m_2 g## can exceed this.

Note: the second exercise has been removed from this thread. The OP is invited to post it in a separate thread.

## What are Newton's three laws of motion?

Newton's three laws of motion are the fundamental principles that describe the behavior of objects in motion. They are:
1. The law of inertia: An object will remain at rest or in uniform motion unless acted upon by an external force.
2. The law of acceleration: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.
3. The law of action and reaction: For every action, there is an equal and opposite reaction.

## How do these laws apply to everyday life?

Newton's laws of motion can be observed in many everyday situations. For example:
1. The law of inertia: A seatbelt keeps a passenger in a car in place when the car suddenly stops, preventing them from flying forward.
2. The law of acceleration: Pushing a shopping cart requires less force to move it when it is empty compared to when it is full.
3. The law of action and reaction: When a person jumps off a boat, the boat moves in the opposite direction due to the force of the person's jump.

## What is the difference between mass and weight?

Mass refers to the amount of matter in an object and is measured in kilograms. Weight, on the other hand, is the force of gravity acting on an object and is measured in Newtons. This means that an object's mass will remain the same regardless of its location, but its weight may change depending on the strength of gravity in that location.

## How did Newton's Laws of Motion revolutionize the field of physics?

Newton's Laws of Motion provided a new understanding of the fundamental principles that govern the behavior of objects in motion. These laws allowed scientists to make accurate predictions about the motion of objects and laid the foundation for further advancements in the field of physics, including the development of calculus and the theory of gravitation.

## Do Newton's Laws of Motion apply to all objects?

Newton's Laws of Motion apply to all objects, regardless of their size or mass. However, they may not always be noticeable in everyday life due to the presence of other external forces, such as friction or air resistance, that can affect an object's motion.

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