Weight

Weight, Mass and Gravity

Open Ended

Starter: you place an object on a set of scales. The scales read 8kg. 8kg is the objects...

Mass

Mass is the amount of matter there is in an object

It is measured in kilograms which is often shortened to Kg (this should give you a clue for your starter task)

Weight

Weight is a force.

The unit of weight is the newton, N. 

Weight occurs due to gravity.

What is gravity?

• Gravity pulls everything towards the centre of a mass

• Gravity is measured in N/Kg

Larger objects have a greater gravitational field strength.

The gravitational field strength on Earth is 10 N/Kg

Larger planets will have a larger gravitational field strength.

Multiple Choice

Which planet will have the greatest gravitational field strength?

• Mercury

• Earth

• Jupiter

• Neptune

Multiple Choice

Which planet will have the smallest gravitational field strength?

• Mercury

• Earth

• Jupiter

• Neptune

Multiple Choice

The gravitational field strength on Earth is 10N/Kg. Which of the following could be the gravitational field strength of Saturn?

• 9N/Kg

• 10N/Kg

• 11N/Kg

Mass will stay the same no matter what planet you are on.

However, as weight is dependent on gravity it will change depending on what planet you are on.

example 1

Max is stood on Earth (gravitational field strength=10N/Kg) and has a mass of 50Kg. What is his weight?

 $W=m\times g$   

 $W=\ 50\times10$   

 $W=500N$  

Max then flies to Mars which has a gravitational field strength of 4N/Kg. What is his new weight? 

 $W=m\times g$   
 $W=\ 50\times4$   
 $W=\ 200N$  

Multiple Choice

Max (50Kg) then travels to Venus which has a gravitational field strength of 9N/Kg. What is his new weight?

• 9N

• 50N

• 450N

• 500N

Multiple Choice

Which of the following is measured in Newtons?

• Mass

• Weight

• Gravity

Multiple Choice

Which of the following is measured in Kg?

• Mass

• Weight

• Gravity

Multiple Choice

Which of the following is measured in N/Kg?

• Mass

• Weight

• Gravity

Multiple Choice

Which of the following stays the same no matter what planet you are on?

• Mass

• Weight

• Gravity

Multiple Choice

What is the gravitational field strength on Earth?

• 1Kg

• 1N/Kg

• 10Kg

• 10N/Kg

Multiple Choice

A baby elephant has a mass of 100Kg. What is its weight on Earth?

• 100Kg

• 10N

• 1000N

• 2000N

Poll

How confident do you feel with mass, weight and gravity.

• Very confident

• Confident

• Not at all confident