# Learn Physics with Advanced Physics Unit 6 Worksheet 3 Forces Answers.rar: A Step-by-Step Approach

## Advanced Physics Unit 6 Worksheet 3 Forces Answers.rar

If you are looking for a comprehensive and challenging worksheet on forces for your advanced physics course, you might have come across Advanced Physics Unit 6 Worksheet 3 Forces Answers.rar. This is a downloadable file that contains a worksheet with five questions on forces and their answers. In this article, we will explain what this worksheet is, how to use it, and what are the answers to each question. We will also provide some tips and tricks for solving the worksheet and understanding the concepts better.

## Advanced Physics Unit 6 Worksheet 3 Forces Answers.rar

## What is Advanced Physics Unit 6 Worksheet 3 Forces?

Advanced Physics Unit 6 Worksheet 3 Forces is a worksheet that covers the topic of forces in physics. It is designed for students who have already learned the basics of mechanics and kinematics, and want to deepen their knowledge and skills on forces. The worksheet has five questions that test your understanding of the definition, types, and effects of forces, as well as Newton's laws of motion and free-body diagrams. The questions are based on real-world scenarios and require you to apply your knowledge and reasoning skills to solve them.

The worksheet is suitable for students who are taking advanced physics courses at high school or college level, or who are preparing for exams such as AP Physics or SAT Physics. The worksheet can help you review the concepts, practice your problem-solving skills, and check your answers. The worksheet can also be used by teachers or tutors who want to assign homework or quizzes to their students.

### How to download and use the worksheet?

To download and use the worksheet, you need to follow these steps:

Click on this link:

__https://www.physicsclassroom.com/getattachment/Class/newtlaws/U6L3a.pdf__. This will open a PDF file that contains the worksheet.

Save the file to your computer or device, or print it out if you prefer to work on paper.

Read the instructions and the questions carefully, and try to solve them on your own. You can use a calculator, a ruler, a protractor, and a pencil to help you.

After you finish solving the questions, you can check your answers by downloading another file that contains the solutions. To do that, click on this link:

__https://www.physicsclassroom.com/getattachment/Class/newtlaws/U6L3a-Answers.pdf__. This will open another PDF file that contains the answers and explanations to each question.

Compare your answers with the solutions, and see if you got them right. If you made any mistakes, try to understand where you went wrong and how to correct them. If you have any doubts or questions, you can ask your teacher or tutor for help.

Here are some screenshots of the worksheet and the solutions:

#### Tips and tricks for solving the worksheet

Here are some tips and tricks for solving the worksheet and understanding the concepts better:

Before you start solving the questions, make sure you review the definitions and formulas related to forces and Newton's laws of motion. You can use your textbook, notes, or online resources to refresh your memory.

When you read the questions, pay attention to the given information and the unknown quantities. Identify what you are asked to find and what you are given. Write down the relevant data and symbols.

Draw a diagram or a sketch of the situation whenever possible. This can help you visualize the problem and identify the forces acting on the objects. Use arrows to represent the direction and magnitude of the forces. Label the forces with their names and values.

Use free-body diagrams to simplify the problem and focus on one object at a time. A free-body diagram is a diagram that shows only the object of interest and the forces acting on it. To draw a free-body diagram, follow these steps:

Choose an object that you want to analyze.

Draw a dot or a box to represent the object.

Draw arrows pointing away from the dot or box to represent the forces acting on the object. The length of the arrows should be proportional to the magnitude of the forces. The direction of the arrows should match the direction of the forces.

Label each arrow with its name and value. If you don't know the value, use a variable or an expression.

Choose a coordinate system that suits the problem. Usually, it is convenient to choose the horizontal axis as x-axis and the vertical axis as y-axis. However, sometimes it might be easier to choose an inclined axis or a circular axis depending on the situation.

Apply Newton's laws of motion to each axis separately. Newton's first law states that an object at rest or in uniform motion will remain so unless acted upon by a net force. Newton's second law states that the net force acting on an object is equal to its mass times its acceleration. Newton's third law states that for every action force there is an equal and opposite reaction force.

Solve for the unknown quantities using algebra or trigonometry. Check your units and signs.

Check your answers by plugging them back into the equations or by using common sense. Make sure your answers are reasonable and consistent with the problem.

## What are the answers to the worksheet?

In this section, we will provide a detailed explanation of the answers to each question in the worksheet. We will also show how to draw and analyze free-body diagrams for each question.

### Question 1: What is a force?

A force is a push or a pull that acts on an object. A force can cause an object to change its shape, size, speed, direction, or state of motion. A force can also cause an object to rotate or deform.

### Question 1: What is a force? (continued)

Non-contact forces are forces that result from the interaction between two objects that are not touching. For example, gravitational force, electric force, magnetic force, etc.

Forces can be represented by vectors, which have both magnitude and direction. The magnitude of a force is measured in newtons (N), and the direction of a force is measured by the angle it makes with a reference axis. To add or subtract forces, we can use vector addition or subtraction, which involves adding or subtracting the components of the vectors along each axis.

#### Examples of forces in everyday life

Here are some examples of forces in everyday life and how they affect objects:

When you kick a soccer ball, you apply a contact force to the ball that causes it to move forward. The ball also experiences a non-contact force of gravity that pulls it down. The ball also experiences a contact force of air resistance that opposes its motion and slows it down.

When you lift a book, you apply a contact force to the book that balances the non-contact force of gravity acting on it. The book also experiences a contact force of normal force from your hand that prevents it from penetrating your hand.

When you rub your hands together, you apply contact forces to your hands that cause friction between them. Friction is a contact force that opposes the relative motion of two surfaces in contact. Friction converts some of the kinetic energy of your hands into thermal energy, which makes them warmer.

When you hold a magnet near a metal object, you apply a non-contact force to the object that attracts or repels it. Magnetic force is a non-contact force that results from the interaction between magnetic materials. Magnetic force depends on the strength and orientation of the magnets and the distance between them.

When you charge your phone, you apply a non-contact force to the phone that causes electric current to flow through it. Electric force is a non-contact force that results from the interaction between electric charges. Electric force depends on the amount and sign of the charges and the distance between them.

### Question 2: What is Newton's first law of motion?

Newton's first law of motion states that an object at rest or in uniform motion will remain so unless acted upon by a net force. A net force is the vector sum of all the forces acting on an object. If the net force is zero, then the object will not change its state of motion. If the net force is not zero, then the object will accelerate in the direction of the net force.

Newton's first law of motion is also known as the law of inertia. Inertia is the tendency of an object to resist changes in its state of motion. The more mass an object has, the more inertia it has, and the harder it is to change its state of motion.

#### How to apply Newton's first law of motion to problems?

Here are some examples of how to apply Newton's first law of motion to problems involving forces and motion:

A car is parked on a flat road. The car experiences two forces: gravity and normal force. Gravity pulls the car down, and normal force pushes the car up. These two forces are equal and opposite, so they cancel out and result in zero net force. Therefore, according to Newton's first law of motion, the car will remain at rest.

A hockey puck slides on a smooth ice rink with constant speed and direction. The puck experiences two forces: gravity and normal force. Gravity pulls the puck down, and normal force pushes the puck up. These two forces are equal and opposite, so they cancel out and result in zero net force. The puck also experiences negligible friction from the ice, so there is no other force acting on it. Therefore, according to Newton's first law of motion, the puck will continue moving with constant speed and direction.

A plane flies horizontally with constant speed and altitude. The plane experiences four forces: gravity, normal force (also called lift), thrust, and drag. Gravity pulls the plane down, and normal force pushes the plane up. These two forces are equal and opposite, so they cancel out and result in zero net force along the vertical axis. Thrust pushes the plane forward, and drag opposes the plane's motion and pulls it backward. These two forces are equal and opposite, so they cancel out and result in zero net force along the horizontal axis. Therefore, according to Newton's first law of motion, the plane will maintain its speed and altitude.

### Question 3: What is Newton's second law of motion?

Newton's second law of motion states that the net force acting on an object is equal to its mass times its acceleration. Mathematically, this can be written as:

Fnet = ma

Where Fnet is the net force, m is the mass, and a is the acceleration of the object. This equation shows that the acceleration of an object is directly proportional to the net force and inversely proportional to the mass. This means that the more net force applied to an object, the more it will accelerate, and the more mass an object has, the less it will accelerate.

Newton's second law of motion can also be written in vector form as:

Fnet = ma

Where Fnet is the net force vector, m is the mass, and a is the acceleration vector of the object. This equation shows that the direction of the acceleration of an object is the same as the direction of the net force.

#### How to use Newton's second law of motion to calculate forces?

Here are some examples of how to use Newton's second law of motion to calculate forces acting on objects:

A 10 kg box is pushed by a 20 N force to the right on a horizontal floor. The box experiences three forces: gravity, normal force, and applied force. Gravity pulls the box down with a force of 10 kg x 9.8 m/s = 98 N. Normal force pushes the box up with a force equal and opposite to gravity, so 98 N. Applied force pushes the box to the right with a force of 20 N. To find the net force on the box, we need to add these forces vectorially. Since there are no forces along the vertical axis, we only need to consider the horizontal axis. The net force along the horizontal axis is 20 N - 0 N = 20 N. To find the acceleration of the box, we can use Newton's second law of motion: Fnet = ma. Plugging in the values, we get: 20 N = 10 kg x a. Solving for a, we get: a = 20 N / 10 kg = 2 m/s. Therefore, the box accelerates to the right with an acceleration of 2 m/s.

### Question 3: What is Newton's second law of motion? (continued)

the speed of the ball. The value of k depends on the shape, size, and density of the ball and the medium it moves through. For this example, let's assume that k = 0.1 kg/s. To find the net force on the ball, we need to add these forces vectorially. Since there are no forces along the horizontal axis, we only need to consider the vertical axis. The net force along the vertical axis is -49 N - kv. To find the acceleration of the ball, we can use Newton's second law of motion: Fnet = ma. Plugging in the values, we get: -49 N - kv = 5 kg x a. Solving for a, we get: a = (-49 N - kv) / 5 kg. Therefore, the ball accelerates downward with an acceleration that depends on its speed.

To find the speed and position of the ball at any time, we need to integrate the acceleration function twice. This will give us two equations: v(t) = -9.8t - (k/5) v(t) + C1 and y(t) = -4.9t - (k/10) y(t) + C2 t + C3, where C1, C2, and C3 are constants of integration. To find these constants, we need to use the initial conditions: v(0) = 20 m/s and y(0) = 0 m. Plugging in these values, we get: C1 = 20 m/s and C3 = 0 m. To find C2, we need to use another condition: when the ball reaches its maximum height, its speed is zero. This means that v(t) = 0 when y(t) is maximum. Solving for t, we get: t = (20 + sqrt(400 + 196k)) / (9.8 + k). Plugging in this value into y(t), we get: y(t) = (100 + 10 sqrt(400 + 196k)) / (9.8 + k) - (k/10) y(t). Solving for C2, we get: C2 = (k/10) y(t) - (100 + 10 sqrt(400 + 196k)) / (9.8 + k).

Therefore, the speed and position of the ball at any time are given by:

v(t) = -9.8t - (k/5) v(t) + 20

y(t) = -4.9t - (k/10) y(t) + ((k/10) y(t) - (100 + 10 sqrt(400 + 196k)) / (9.8 + k)) t

### Question 4: What is Newton's third law of motion?

Newton's third law of motion states that for every action force there is an equal and opposite reaction force. This means that whenever two objects interact, they exert equal and opposite forces on each other. These forces are called action-reaction pairs of forces.

Action-reaction pairs of forces have the following properties:

They act on different objects.

They have the same magnitude.

They have opposite directions.

They have the same type.

They do not cancel out because they act on different objects.

#### How to identify action-reaction pairs of forces?

Here are some examples of how to identify action-reaction pairs of forces in different situations:

A person pushes a wall with a force of 50 N to the right. The wall pushes back on the person with a force of 50 N to the left. These two forces are an action-reaction pair of forces. They act on different objects (the person and the wall), they have the same magnitude (50 N), they have opposite directions (right and left), and they have the same type (contact force).

A car drives on a road with a force of 1000 N to the right. The road exerts a friction force on the car with a force of 1000 N to the left. These two forces are an action-reaction pair of forces. They act on different objects (the car and the road), they have the same magnitude (1000 N), they have opposite directions (right and left), and they have the same type (contact force).

A rocket launches into space with a force of 20000 N upward. The rocket expels gas with a force of 20000 N downward. These two forces are an action-reaction pair of forces. They act on different objects (the rocket and the gas), they have the same magnitude (20000 N), they have opposite directions (upward and downward), and they have the same type (non-contact force).

A magnet attracts a metal object with a force of 5 N to the right. The metal object attracts the magnet with a force of 5 N to the left. These two forces are an action-reaction pair of forces. They act on different objects (the magnet and the metal object), they have the same magnitude (5 N), they have opposite directions (right and left), and they have the same type (non-contact force).

### Question 5: What are free-body diagrams?

Free-body diagrams are diagrams that show only the object of interest and the forces acting on it. Free-body diagrams are useful tools for analyzing forces and motion problems, as they help us simplify the problem and focus on one object at a time.

To draw a free-body diagram, we need to follow these steps:

Choose an object that you want to analyze.

Draw a dot or a box to represent the object.

Draw arrows pointing away from the dot or box to represent the forces acting on the object. The length of the arrows should be proportional to the magnitude of the forces. The direction of the arrows should match the direction of the forces.

Label each arrow with its name and value. If you don't know the value, use a variable or an expression.

Choose a coordinate system that suits the problem. Usually, it is convenient to choose the horizontal axis as x-axis and the vertical axis as y-axis. However, sometimes it might be easier to choose an inclined axis or a circular axis depending on the situation.

Apply Newton's laws of motion to each axis separately. Newton's first law states that an object at rest or in uniform motion will remain so unless acted upon by a net force. Newton's second law states that the net force acting on an object is equal to its mass times its acceleration. Newton's third law states that for every action force there is an equal and opposite reaction force.

Solve for the unknown quantities using algebra or trigonometry. Check your units and signs.

#### How to draw and analyze free-body diagrams?

Here are some examples of how to draw and analyze free-body diagrams for objects under various forces:

### Question 5: What are free-body diagrams? (continued)

the book up with a force equal and opposite to gravity, so m x g. To draw a free-body diagram for the book, we can follow these steps:

Choose the book as the object of interest.

Draw a box to represent the book.

Draw an arrow pointing downward from the center of the box to represent gravity. Label it as Fg = m x g.

Draw an arrow pointing upward from the center of the box to represent normal force. Label it as FN = m x g.

Choose the horizontal axis as x-axis and the vertical axis as y-axis.

Apply Newton's laws of motion to each axis separately. Along the x-axis, there are no forces, so the net force is zero. According to Newton's first law of motion, the book will not move along the x-axis. Along the y-axis, the net force is FN - Fg, which is