The measuring device shown is used to measure the weight of an object. Lesson Starter The measuring device shown is used to measure the weight of an object. What is the name of the measuring device? Which unit is force measured in? A bag of sugar has a mass of 500g- what does it weigh on earth?

To explore the weight of masses on different planets Learning Intention To explore the weight of masses on different planets

Mass and Weight 1666 Isaac Newton why objects fall to the ground and why the Moon goes round the Earth. force of gravity pulled objects towards each other. Isaac`s ideas were: All objects attract each other with a force called Gravity. The size of the force of gravity depends on the amount of mass each object has. The force of gravity also depends on the distance between each object.

Different planets, different weights Different forces of gravity on different planet = DIFFERENT WEIGHT Weight depends on the planets GRAVITATIONAL FIELD STRENGTH Gravitational field strength is weight of 1kg on the surface of the planet Example 1 kg on earth = 10 N Person = 70Kg Weight = mass x gravitational field strength Weight = 70 x 10

Gravitational Field Strength (copy) The weight of an object on a planet depends on the planet’s gravitational field strength (GFS). The GFS of a planet is the WEIGHT of a 1kg mass on the surface of the planet. To work out the weight of an object we can use the equation Weight = mass x gravitational field strength

Task Jamie weighs 85kg; use the data provided to calculate what his WEIGHT would be on each planet. Weight = mass x gravitational field strength

PLANET GFS (N/kg) Jamie’s weight (N) Mercury 3.8 Venus 9.0 Mars 3.4 Jupiter 26 Saturn 11.6 Uranus 11.1 Neptune 12.1

Planet Display