03/05/23

Gravity and SpaceGravity and Space

03/05/23GravityGravityGravity is an attractive force that affects anything with mass:

Note that this force goes both ways – the Earth

is attracted to us.

03/05/23GravityGravityGravity depends on 2 things:

If you double the distance the

gravitational force divides by 4…

F

F/4

1) The mass of the objects

2) The distance between them

F 2F

If you double the mass of one object

you double the force

03/05/23Weight vs. MassWeight vs. MassEarth’s Gravitational Field Strength is 10N/kg. In other

words, a 1kg mass is pulled downwards by a force of 10N.

W

gM

Weight = Mass x Gravitational Field Strength (in N) (in kg) (in N/kg)

1) What is the weight on Earth of a book with mass 2kg?2) What is the weight on Earth of an apple with mass 100g?3) Dave weighs 700N. What is his mass?4) On the moon the gravitational field strength is 1.6N/kg. What will

Dave weigh if he stands on the moon?

03/05/23RocketsRocketsWhen a rocket flies away from Earth the force needed to keep it accelerating decreases:

This is because…1) As the rocket gets further away from Earth the force of ______ decreases.2) As the rocket burns fuel it gets _______, also decreasing the gravity downwards.

Words – gravity, smaller, large, lighter

_____ force needed here

_____ force needed here

03/05/23Natural SatellitesNatural SatellitesMercury

MarsJupiter

Saturn

Neptune

Uranus

Pluto

VenusEarth

These planets are all satellites of the sun