**View:**

**Sorted by:**

### Conservative and Nonconservative Forces in Physics

In physics, it’s important to know the difference between conservative and nonconservative forces. The work a *conservative force* does on an object is path-independent; the actual path taken by the object [more…]

### The Principle of Conservation of Mechanical Energy

In physics, if you know the kinetic and potential energies that act on an object, then you can calculate the mechanical energy of the object. Imagine a roller coaster car traveling along a straight stretch [more…]

### Use the Principle of Conservation of Mechanical Energy to Find an Object’s Final Speed

Thanks to the principle of conservation of mechanical energy, you can use physics to calculate the final speed of an object that starts from rest.

“Serving as a roller coaster test pilot is a tough gig, [more…]

### Use the Principle of Conservation of Mechanical Energy to Find the Final Height of a Moving Object

Thanks to the principle of conservation of mechanical energy, you can use physics to determine the final height of a moving object. At this very moment, for example, suppose Tarzan is swinging on a vine [more…]

### How to Calculate Work That Is Opposite the Direction of an Object’s Motion

In physics, if a force on an object has a component in the same direction as the motion, the work that force does on the object is positive. If a force on an object has a component in the opposite direction [more…]

### How to Calculate the Kinetic Energy of an Object

You can use physics to calculate the kinetic energy of an object. When you start pushing or pulling a stationary object with a constant force, it starts to move if the force you exert is greater than the [more…]

### How to Calculate Changes in Kinetic Energy Using Net Force

In physics, if you want to find the change in an object’s kinetic energy, you have to consider only the work done by the net force acting on the object. In other words, you convert only the work done by [more…]

### Calculating Average Speed Based on Distance and Time

In physics, average speed is the total distance you travel divided by the total time it takes. Speed is represented by the variable *v*, and average speed is sometimes written as [more…]

### How to Calculate Power Based on Force and Speed

In physics, you can calculate power based on force and speed. Because work equals force times distance, you can write the equation for power the following way, assuming that the force acts along the direction [more…]

### How Impulse Affects Momentum

In physics terms, impulse tells you how much the momentum of an object will change when a force is applied for a certain amount of time. Say, for example, that you’re shooting pool. Instinctively, you [more…]

### How to Find the Velocity of an Object before Collision

In physics, the principle of conservation of momentum comes in handy when you can’t measure velocity with a simple stopwatch. Say, for example, that you accept a consulting job from an ammunition manufacturer [more…]

### Calculating Tangential Acceleration on a Curve

In physics, *t**angential acceleration* is a measure of how the tangential velocity of a point at a certain radius changes with time. Tangential acceleration is just like linear acceleration, but it’s specific [more…]

### How to Calculate Centripetal Acceleration of an Orbiting Object

In physics, you can apply Newton’s first and second laws to calculate the centripetal acceleration of an orbiting object. Newton’s first law says that when there are no net forces, an object in motion [more…]

### How Angular Acceleration Works

If the angular velocity vector points out of the plane of rotation on a wheel, you can use physics to determine what happens when the angular velocity changes — when the wheel speeds up or slows down. [more…]

### How to Calculate Torque That Is Not Perpendicular to the Lever Arm

Using principles of physics, if you push a partially open door in the same direction as you push a closed door, you create a different torque because of the non-right angle between your force and the door [more…]

### How to Calculate Rotational Equilibrium

You can use physics to calculate the amount of force needed to offset torque and maintain rotational equilibrium. For example, say the manager at the hardware store you work at asks you to help hang a [more…]

### How Friction Affects Rotational Equilibrium

You can use physics to calculate how friction affects rotational equilibrium. For example, say a hardware store owner comes to you for help with a problem. A clerk has climbed near the top of a ladder [more…]

### How to Calculate the Torque Needed to Accelerate a Spinning Disc

You can use physics to calculate the amount of torque needed to accelerate (or decelerate) the speed of a spinning disc. Without the ability to change the speed of a disc, it would be impossible for you [more…]

### Tracking Simple Harmonic Motion of a Moving Object over Time

In physics, tracking simple harmonic motion can require time and patience when you have to figure out how the motion of an object changes over time.

Imagine that one day you come up with a brilliant idea [more…]

### Calculating the Acceleration of an Object in Simple Harmonic Motion

In physics, you can calculate the acceleration of an object in simple harmonic motion as it moves in a circle; all you need to know is the object’s path radius and angular velocity. [more…]

### Calculating Heat Exchange in a Closed System

In physics, you can calculate how much heat energy is required to raise an object of a certain mass by a certain temperature — all you need is the object’s specific heat. [more…]

### How to Calculate the Latent Heat Needed to Cause a Phase Change

In physics, *l**atent heat* is the heat per kilogram that you have to add or remove to make an object change its state; in other words, latent heat is the heat needed to make a phase change happen. Its units [more…]

### Counting Molecules Using Avogradro's Number

To look at gases on the molecular level, you need to know how many molecules you have in a certain sample. Physicists use a measurement called a *mole* to relate the mass of a sample to the number of molecules [more…]

### Using Boyle's and Charles's Laws to Express the Ideal Gas Law

In physics, you can use Boyle’s and Charles’s laws to express the ideal gas law in different ways. For example, you can express the relationship between the pressure and volume of an ideal gas before and [more…]

### Calculating Kinetic Energy in an Ideal Gas

Molecules have very little mass, but gases contain many, many molecules, and because they all have kinetic energy, the total kinetic energy can pile up pretty fast. Using physics, can you find how much [more…]