Momentum
If an object is moving, it has momentum. This is what keeps an object moving in the same direction. The more momentum something has, the harder it is to change its direction or bring it to a stop.
So we can work out an object's momentum using the equation:
Momentum = mass × velocity
During an explosion or collision, the total momentum is conserved. This means the total momentum before the event is equal to the total momentum after the event. This is useful for studying collisions in space or stellar explosions.
Gravity
Gravity is the name of the force that pulls objects together. It is a non-contact force. This means it acts on objects that are not touching each other.
- Gravitational Field Strength
All objects with mass have a gravitational field. We measure the gravitational field strength (g) in N/kg. The more mass an object has, the greater its gravitational field strength will be.
On Earth, g = 9.8 N/kg.
- Weight
Weight is the force acting on an object due to gravity. It is measured in Newtons (N). You can calculate weight using this equation.
Weight = Mass x Gravitational Field Strength
Kepler's Laws: Find the Mass of the Sun
Many years ago, a mathematician named Johannes Kepler created a set of rules explaining planets' movement in our Solar System.
Calculate Your Weight on Another Planet
The 'Space Weight' Calculator
Ever wondered how heavy or light you would feel on another planet in our Solar System?
Gravity Simulator
Is gravity the same everywhere? Experiment with how the ball reacts in each of the Solar System locations by dropping or throwing the ball. How similar or different is each location to Earth?
