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# 6: Applications of Newton

• 6.1: Prelude to Applications of Newton's Laws
Car racing has grown in popularity in recent years. As each car moves in a curved path around the turn, its wheels also spin rapidly. The wheels complete many revolutions while the car makes only part of one (a circular arc). How can we describe the velocities, accelerations, and forces involved? What force keeps a racecar from spinning out, hitting the wall bordering the track? What provides this force? Why is the track banked? We answer all of these questions in this chapter as we expand our c
• 6.2: Solving Problems with Newton's Laws (Part 1)
Newton’s laws of motion can be applied in numerous situations to solve motion problems. Some problems contain multiple force vectors acting in different directions on an object.
• 6.3: Solving Problems with Newton's Laws (Part 2)
Some motion problems contain several physical quantities, such as forces, acceleration, velocity, or position. You can apply concepts from kinematics and dynamics to solve these.
• 6.4: Friction (Part 1)
When a body is in motion, it has resistance because the body interacts with its surroundings. This resistance is a force of friction. Friction opposes relative motion between systems in contact but also allows us to move, a concept that becomes obvious if you try to walk on ice. Friction is a common yet complex force, and its behavior still not completely understood. Still, it is possible to understand the circumstances in which it behaves.
• 6.5: Friction (Part 2)
Simple friction is always proportional to the normal force. When an object is not on a horizontal surface, as with an inclined plane, the force acting on the object that is directed perpendicular to the surface needs to be found.
• 6.6: Centripetal Force
Centripetal force is a “center-seeking” force that always points toward the center of rotation so it is perpendicular to linear velocity. Rotating and accelerated frames of reference are noninertial. Inertial forces, such as the Coriolis force, are needed to explain motion in such frames.
• 6.7: Drag Force and Terminal Speed
Drag forces acting on an object moving in a fluid oppose the motion. For larger objects (such as a baseball) moving at a velocity in air, the drag force is determined using the drag coefficient, the area of the object facing the fluid, and the fluid density. For small objects (such as a bacterium) moving in a denser medium, the drag force is given by Stokes’ law.
• 6.8: Applications of Newton's Laws (Exercises)
• 6.9: Applications of Newton's Laws (Summary)
• 6.11: Introduction to UCM and Gravitation
Uniform circular motion is a motion in a circular path at constant speed.
• 6.12: Non-Uniform Circular Motion
Non-uniform circular motion denotes a change in the speed of a particle moving along a circular path.
• 6.13: Velocity, Acceleration, and Force
The rotational angle is a measure of how far an object rotates, and angular velocity measures how fast it rotates.
• 6.14: Types of Forces in Nature
Tides are the rise and fall of sea levels due to the effects of the gravity exerted by the moon and the sun, and the rotation of the Earth.
• 6.15: Newton’s Law of Universal Gravitation
Objects with mass feel an attractive force that is proportional to their masses and inversely proportional to the square of the distance.
• 6.16: Kepler’s Laws
Kepler’s first law is: The orbit of every planet is an ellipse with the Sun at one of the two foci.
• 6.17: Gravitational Potential Energy
Gravitational energy is the potential energy associated with gravitational force, such as elevating objects against the Earth’s gravity.
• 6.18: Energy Conservation
An object reaches escape speed when the sum of its kinetic energy and its gravitational potential energy is equal to zero.
• 6.19: Angular vs. Linear Quantities
The familiar linear vector quantities such as velocity and momentum have analogous angular quantities used to describe circular motion.