Impulse and momentum are physical concepts that are easily seen from Newton’s Laws of Motion. Start with this equation of motion for constant acceleration. v = v0 + at where v = velocity v0 = initial velocity a = acceleration t = time If you rearrange the equation, you get […]

# Physics Example Problems

Special relativity theory introduced an interesting notion about time. Time does not pass at the same rate for moving frames of reference. Moving clocks run slower than clocks in a stationary frame of reference. This effect is known as time dilation. To calculate this time difference, a Lorentz transformation is […]

## Moving Clocks Run Slower – Time Dilation

Relativity tells us moving objects will have different lengths in the direction of motion, depending on the frame of reference of the observer. This is known as length contraction. This type of problem can be reduced to two different frames of reference. One is the frame of reference where a […]

## Moving Rulers Are Shorter – Length Contraction Example Problem

This wavelength and energy example problem will show how to find the energy of a photon from its wavelength. First, let’s look at the physics of the problem. The energy of a single photon of light is dependent on its frequency. This relationship is expressed in the equation E = […]

## Wavelength and Energy Example Problem

Momentum is a measurement of inertia in motion. When a mass has velocity, it has momentum. Momentum is calculated by the equation momentum = mass x velocity momentum = mv This conservation of momentum example problem illustrates the principle of conservation of momentum after a collision between two objects. Problem: […]

## Conservation of Momentum Example Problem

Consider a string with a weight tied to the end. Gravity pulls the string down while the string pulls the weight. These two forces are equal and opposite to each other. Together, they cancel each other out. The weight is “at rest” with no net forces acting on it. This state […]