Example Physics Problems and Solutions

Equilibrium Example Problem 1

Learning how to solve physics problems is a big part of learning physics. Here’s a collection of example physics problems and solutions to help you tackle problems sets and understand concepts and how to work with formulas:

Physics Homework Tips
Physics homework can be challenging! Get tips to help make the task a little easier.

Unit Conversion Examples

There are now too many unit conversion examples to list in this space. This Unit Conversion Examples page is a more comprehensive list of worked example problems.

Newton’s Equations of Motion Example Problems
Projectile motion problem setup illustration

Equations of Motion – Constant Acceleration Example
This equations of motion example problem consist of a sliding block under constant acceleration. It uses the equations of motion to calculate the position and velocity of a given time and the time and position of a given velocity.

Equations of Motion Example Problem – Constant Acceleration
This example problem uses the equations of motion for constant acceleration to find the position, velocity, and acceleration of a breaking vehicle.

Equations of Motion Example Problem – Interception

This example problem uses the equations of motion for constant acceleration to calculate the time needed for one vehicle to intercept another vehicle moving at a constant velocity.

well drop setup illustration

Vertical Motion Example Problem – Coin Toss
Here’s an example applying the equations of motion under constant acceleration to determine the maximum height, velocity and time of flight for a coin flipped into a well. This problem could be modified to solve any object tossed vertically or dropped off a tall building or any height. This type of problem is a common equation of motion homework problem.

Projectile Motion Example Problem
This example problem shows how to find different variables associated with parabolic projectile motion.


Accelerometer and Inertia Example Problem
Accelerometers are devices to measure or detect acceleration by measuring the changes that occur as a system experiences an acceleration. This example problem uses one of the simplest forms of an accelerometer, a weight hanging from a stiff rod or wire. As the system accelerates, the hanging weight is deflected from its rest position. This example derives the relationship between that angle, the acceleration and the acceleration due to gravity. It then calculates the acceleration due to gravity of an unknown planet.

Weight In An Elevator
Have you ever wondered why you feel slightly heavier in an elevator when it begins to move up? Or why you feel lighter when the elevator begins to move down? This example problem explains how to find your weight in an accelerating elevator and how to find the acceleration of an elevator using your weight on a scale.

Equilibrium Example Problem
This example problem shows how to determine the different forces in a system at equilibrium. The system is a block suspended from a rope attached to two other ropes.

Equilibrium Cat 1

Equilibrium Example Problem – Balance
This example problem highlights the basics of finding the forces acting on a system in mechanical equilibrium.

Force of Gravity Example
This physics problem and solution shows how to apply Newton’s equation to calculate the gravitational force between the Earth and the Moon.

Coupled Systems Example Problems

Atwood Machine
Simple Atwood Machine

Coupled systems are two or more separate systems connected together. The best way to solve these types of problems is to treat each system separately and then find common variables between them.
Atwood Machine
The Atwood Machine is a coupled system of two weights sharing a connecting string over a pulley. This example problem shows how to find the acceleration of an Atwood system and the tension in the connecting string.
Coupled Blocks – Inertia Example
This example problem is similar to the Atwood machine except one block is resting on a frictionless surface perpendicular to the other block. This block is hanging over the edge and pulling down on the coupled string. The problem shows how to calculate the acceleration of the blocks and the tension in the connecting string.

Friction Example Problems

friction slide setup

These example physics problems explain how to calculate the different coefficients of friction.

Friction Example Problem – Block Resting on a Surface
Friction Example Problem – Coefficient of Static FrictionFriction Example Problem – Coefficient of Kinetic Friction
Friction and Inertia Example Problem

Momentum and Collisions Example Problems

Desktop Momentum Balls Toy

These example problems show how to calculate the momentum of moving masses.

Momentum and Impulse Example
Finds the momentum before and after a force acts on a body and determine the impulse of the force.

Elastic Collision Example
Shows how to find the velocities of two masses after an elastic collision.

It Can Be Shown – Elastic Collision Math Steps
Shows the math to find the equations expressing the final velocities of two masses in terms of their initial velocities.

Simple Pendulum Example Problems

These example problems show how to use the period of a pendulum to find related information.

Find the Period of a Simple Pendulum
Find the period if you know the length of a pendulum and the acceleration due to gravity.

Find the Length of a Simple Pendulum
Find the length of the pendulum when the period and acceleration due to gravity is known.

Find the Acceleration due to Gravity Using A Pendulum
Find ‘g’ on different planets by timing the period of a known pendulum length.

Harmonic Motion and Waves Example Problems

Hooke's Law Forces

These example problems all involve simple harmonic motion and wave mechanics.

Energy and Wavelength Example
This example shows how to determine the energy of a photon of a known wavelength.

Hooke’s Law Example Problem
An example problem involving the restoring force of a spring.

Wavelength and Frequency Calculations
See how to calculate wavelength if you know frequency and vice versa, for light, sound, or other waves.

Heat and Energy Example Problems

Heat of Fusion Example Problem
Two example problems using the heat of fusion to calculate the energy required for a phase change.

Specific Heat Example Problem
This is actually 3 similar example problems using the specific heat equation to calculate heat, specific heat, and temperature of a system.

Heat of Vaporization Example Problems
Two example problems using or finding the heat of vaporization.

Ice to Steam Example Problem
Classic problem melting cold ice to make hot steam. This problem brings all three of the previous example problems into one problem to calculate heat changes over phase changes.

Charge and Coulomb Force Example Problems

Setup diagram of Coulomb's Law Example Problem.
Two charges separated by one centimeter experiencing a force of repulsion of 90 N.

Electrical charges generate a coulomb force between themselves proportional to the magnitude of the charges and inversely proportional to the distance between them.
Coulomb’s Law Example
This example problem shows how to use Coulomb’s Law equation to find the charges necessary to produce a known repulsive force over a set distance.
Coulomb Force Example
This Coulomb force example shows how to find the number of electrons transferred between two bodies to generate a set amount of force over a short distance.