# Need an explanation on how to do a question applying Newtons Laws

• Asimans
In summary, the tension in the string is 19.6N and the acceleration of the 2.0 kg mass on the table is 7.0m/s^2. This was calculated by using the equation ΣF=ma and considering the forces acting on each block individually. The tension in the string is the same on both sides of the pulley and the acceleration of each block must be the same in this scenario.
Asimans

## Homework Statement

A 2.0 kg mass , placed on a smooth, level table, is attached by a light string passing over a frictionless pulley to a 5.0 kg mass hanging freely over the edge of a table. Calculate...
a) the tension in the string
b) the acceleration of the 2.0 kg mass on the table.The answer given was
T=14N
a=7.0m/s^2

ΣF=ma

## The Attempt at a Solution

ΣF=ma
Ft + Fg = (5+2)a
Ft + (mg) = (7)9.8
Ft + (49) = (68.6)
Ft = 19.6N

Asimans said:

## Homework Statement

A 2.0 kg mass , placed on a smooth, level table, is attached by a light string passing over a frictionless pulley to a 5.0 kg mass hanging freely over the edge of a table. Calculate...
a) the tension in the string
b) the acceleration of the 2.0 kg mass on the table.

ΣF=ma

## The Attempt at a Solution

ΣF=ma
Ft + Fg = (5+2)a
Ft + (mg) = (7)9.8
Ft + (49) = (68.6)
Ft = 19.6N
Hello, Asimans, welcome to PF! Don't try to do this all at once...look at each block separately. The acceleration is not 'g'. Note that the tension in a cord wrapped around an ideal pulley is the same on both sides of the pulley. Also note that the magnitude of the acceleration of each block must be the same in this example. So look at the lower block first, identify the forces acting on it, and apply your relevant equation. Then look at the other block, and do the same. What do you get?

## 1. What are Newton's Laws?

Newton's Laws of Motion are three fundamental principles that describe the behavior of objects in motion. They were developed by Sir Isaac Newton in the 17th century and are still widely used in modern physics and engineering.

## 2. How do I apply Newton's Laws to a specific question or problem?

The first step in applying Newton's Laws is to identify the forces acting on the object or system in question. Then, use Newton's Second Law (F=ma) to calculate the net force and acceleration. Finally, use Newton's Third Law (for every action, there is an equal and opposite reaction) to consider the interactions between objects.

## 3. What are some common examples of Newton's Laws in everyday life?

Some common examples of Newton's Laws in everyday life include the motion of a ball being thrown, a car accelerating or braking, and a person walking or running.

## 4. Are there any exceptions to Newton's Laws?

Newton's Laws are fundamental principles that describe the behavior of objects in motion. However, there are some situations where they may not apply, such as in extreme conditions like at the atomic or subatomic level, or in cases of very high speeds or strong gravitational forces.

## 5. How can I use Newton's Laws to solve problems in physics?

Newton's Laws are essential tools for solving problems in physics. By understanding how forces and motion are related, you can use Newton's Laws to analyze and predict the behavior of objects in various situations. It is also crucial to practice applying these laws to different types of problems to become comfortable with their use.

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