Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
7 courses
Kepler's Laws and Universal Gravitation
Physics · High School (11–12) · Gravitation
FreeCh 7 · 1/3
The planets move on ellipses, and a planet moves faster when it is near the Sun. Kepler found these rules from many years of observations, and Newton explained them with one law. In this course we study the three laws of Kepler, we write Newton's law of gravitation and find the force between two bodies, and we find how the acceleration due to gravity changes with height, with depth and with the turning of the Earth.
3Lessons12Problems2Python Labs1Question Set1Mock Test
Gravitational Field, Potential Energy and Escape Speed
Physics · High School (11–12) · Gravitation, Work, Energy and Power
FreeCh 7 · 2/3
Why can a rocket leave the Earth, but a ball thrown up with the same speed as a bullet always comes back? In this course we define the gravitational field and the gravitational potential energy, we learn why the energy is negative, we find the field and the potential inside and outside a spherical shell and a solid sphere, and we find the escape speed of a planet.
3Lessons12Problems2Python Labs1Question Set1Mock Test
Satellites and Weightlessness
Physics · High School (11–12) · Gravitation, Circular Motion
FreeCh 7 · 3/3
A satellite does not fall to the Earth, because it falls round it. In this course we find the speed and the period of a satellite, we study its energy and what happens when it is lifted or slowed by the air, we find where a geostationary satellite must be and why a polar satellite sees the whole Earth, and we explain why an astronaut feels weightless.
3Lessons12Problems3Python Labs1Question Set1Mock Test
Free Fall, Relative Velocity and Changing Acceleration
Physics · High School (11–12) · Motion in a Straight Line, Gravitation, Relative Motion
FreeCh 2 · 3/4
A ball thrown up stops for a moment at the top, and a car seems to stand still when another car goes at the same speed beside it. In this course we study free fall with the acceleration due to gravity, we find the velocity of one body as seen from another, and we meet the first use of calculus in physics, for a body whose acceleration changes with time.
3Lessons12Problems3Python Labs1Question Set1Mock Test
The Law of Gravitation
Physics · High School (9–10), General · Gravitation
FreeCh 3 · 1/3
An apple falls from a tree. The Moon does not fall, but it goes round the Earth. Newton saw that one force explains both. Here we learn the law of gravitation, and we find out why the Earth gives every falling thing the same acceleration.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Mass, Weight and Free Fall
Physics · High School (9–10), General · Gravitation, Circular Motion, Motion in a Straight Line
FreeCh 3 · 2/3
Your mass is the same on the Moon, but your weight is not. Why? In this course we separate mass from weight, and we weigh an astronaut on the Moon and on Jupiter. Then we see what happens when only gravity acts, in free fall and in an orbit.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Equations of Motion
Physics · High School (9–10), General · Motion in a Straight Line, Gravitation, Circular Motion
FreeCh 1 · 3/3
When the acceleration is steady, three short equations answer almost every question about motion. How fast? How far? How long? We use them on braking trains and falling stones. Then we look at motion in a circle, and we check everything with a few lines of Python.
3Lessons17Problems1Python Lab1Question Set1Mock Test