A force is a push or a pull

A force is a push or a pull

A force is a push or a pull

A force is measured in Grams

A force is measured in NEWTONS Isaac Newton

A force is measured using a thermometer

A force is measure using a SPRING BALANCE

Friction is an example of a force

Friction is an example of a force Lack of friction

Friction is always bad

Friction can be GOOD

Oil can be used to reduce friction

Oil can be used to reduce friction Oil is a lubricant

Ways to reduce friction v Streamlining

There is no gravity on the moon

There IS gravity on the moon 1. 622 m/s² Moon, Gravity

Mass is measured in kilograms

Mass is measured in kilograms Kg

Forces act in pairs

Forces act in pairs

Gravity and mass are the same

Gravity and mass are NOT the same

Gravity is a force between ALL objects! Gravity

Gravity is a very weak force. The force of gravitational attraction between the brother and sister (when 1 meter apart) is only around 0. 0000004 Newtons!

Gravity The size of the force depends on the mass of the objects. The bigger they are, the bigger the force! Small attractive force Bigger attractive force

Gravity The size of the force also depends on the distance between the objects.

Gravity On the earth, Mt. Stickman’s weight is around 800 N

Gravity On the moon, his weight is around 130 N. Why? 130 N

Gravity In deep space, far away from any planets or stars his weight is almost zero. (He is weightless). Why? Cool!

Mass Mr Stickman has a mass of around 77 kg. This means he is made of 77 kg of blood, bones, hair etc. . 77 kg

Mass On the moon, Mr Stickman hasn’t changed. That means he still has mass of 77 kg

Gravity and mass are NOT the same Weight Mass - The force of gravity on - The mass of an object is the something is called its amount of matter in it weight - Mass is measured in - Weight is a force, measure in grams/kilograms Newtons - The mass of an object - The weight of an object can remains constant change

There is a simple formula to convert mass to weight: Weight (in Newtons)= mass (in kg) x 10

Example: What is the weight of an object of mass 6. 5 kg? Weight=mass(kg) x 10 Weight= 6. 5 x 10 Weight= 65 N

Example: What is the weight of an object of mass 200 g? Weight=mass(kg) x 10 Weight= 0. 2(kg) x 10 Weight= 2 N 200÷ 1000= 0. 2 200 g=0. 2 kg

LEARNING CHECK NEXT WEEK 10 -2 -15 You need to know: - What a force is Examples of forces The effects of forces The units of a force and what it is measured in Advantages/disadvantages of friction How to reduce friction The difference between weight and mass How to calculate the weight of an object given its mass