Courses

A shell bursts in the air into many pieces, but one point of the pieces still follows the smooth path of the shell. In this course we find the centre of mass of a system, we see why only the external forces move it, we use it to solve problems of boats, skaters and bursting shells, and we describe the turning of a rigid body with angular velocity and angular acceleration.

StemPy Lab

Two motors lift the same load to the same height, and one is faster. Two cars crash, and they stick together or bounce apart. In this course we measure how fast work is done with power, we study elastic and inelastic collisions in one and two dimensions, and we use the coefficient of restitution and the ballistic pendulum to find speeds that are hard to measure.

StemPy Lab

When a bus starts suddenly, you lean back. When it stops, you lean forward. Why? In this course we find what a force really does. We learn Newton's three laws, the idea of momentum and impulse, and why a gun kicks back when it fires.

StemPy Lab

Push a toy car with a force. Push a loaded truck with the same force. They do not speed up in the same way. Why not? This course gives the rule. It is Newton's second law. We also meet momentum, which tells us how hard a moving thing is to stop.

StemPy Lab

When you push a wall, the wall pushes you back. This is Newton's third law. It explains how a swimmer moves forward and why a gun moves backward when it fires. At the end we see why the total momentum of colliding objects does not change.

StemPy Lab