Isotoon explains physics by showing the situation moving before the equation. Ask about forces, energy, circuits or waves and get a short animated video with the math tied to what you see.
Physics problems get easier once you can see what is happening before you write an equation. Ask about the situation you are stuck on and watch the forces, fields or energy at work.
Gravity pulls harder on a heavier object, but a heavier object also takes more force to accelerate: that is what mass means in F = ma. The two effects cancel exactly, so without air resistance every object near Earth's surface accelerates at about 9.8 m/s². A feather falls more slowly in air only because the drag on it is large compared with its weight.
Current is how much charge flows past a point each second, measured in amperes. Voltage is the energy each unit of charge gains or loses between two points, measured in volts. A battery supplies the voltage; the current that results depends on the resistance of the circuit, I = V / R. A static shock is a high voltage with very little charge moving, and a car's starter motor draws a large current at only 12 volts.
A wire carrying a current in a magnetic field feels a force at right angles to both. In a motor, a loop of wire sits between magnets, so the force pushes one side of the loop up and the other side down, and the loop turns. A commutator, or the electronics in a brushless motor, reverses the current every half turn so the push keeps going the same way and the loop keeps spinning.
The ones marked 3D become a model you can turn, step through and tap.
Every claim is checked before anything is drawn, and every video lists its sources. See plans