Physics formulas you actually need

Most introductory physics comes down to a handful of formula families. Here are the ones that solve the majority of problems — grouped by topic — plus a free app that works any problem step by step from a photo.

Solve a physics problem

Free on iOS · Step-by-step solutions from a photo

The core formula families

Learn these four groups and you can attack most problems you’ll meet.

Kinematics

Motion: v = u + at, s = ut + ½at², v² = u² + 2as. The backbone of every mechanics problem.

Forces & energy

F = ma, W = Fd, KE = ½mv², PE = mgh. Newton’s laws and the work–energy theorem.

Electricity

V = IR, P = VI, and series/parallel resistance rules for circuit problems.

Thermodynamics

PV = nRT, Q = mcΔT. Gas laws and heat transfer for thermal problems.

How to solve a physics problem

01

Identify given and asked

List known quantities with units and pin down exactly what the question wants.

02

Pick the topic

Kinematics, forces, energy, circuits, or heat — the topic points to the formula family.

03

Choose the formula

Match the knowns and the unknown to a formula that connects them.

04

Solve with units

Rearrange, substitute, and carry units through — the final unit confirms the answer.

05

Check with a photo scan

Snap the problem in Physics AI for a full worked solution and verify your method.

Stuck on a problem?

Physics AI reads any physics problem from a photo and shows the full step-by-step solution — the formulas used and the reasoning at each step, so you learn the method.

Common questions

How do I solve a physics problem step by step?

List what is given and asked, identify the topic, choose the formula linking knowns to unknown, then solve while carrying units. Physics AI shows this full worked process from a photo.

What are the most important physics formulas?

The kinematics equations (v = u + at), Newton’s second law (F = ma), work and energy (W = Fd, KE = ½mv²), Ohm’s law (V = IR), and the ideal gas law (PV = nRT) cover most introductory problems.

Can AI solve physics problems?

Yes. Physics AI reads a problem from a photo and produces a step-by-step solution with the formulas and reasoning at each step — so you learn the method, not just the answer.

Is there a free app to help with physics homework?

Physics AI is free on iOS. Scan a problem for worked solutions, practice problems, and formula sheets across mechanics, thermodynamics, and electromagnetism.