Mass and Weight

Mass and Weight

Year 7 Physics

Match

Match the terms to their definition.

• Mass

• Weight

• Gravity

• Newtons

Amount of matter in an object

Force exerted by gravity on an object

Attraction force between two masses

Units forces are measured in

• Amount of matter in an object

• Force exerted by gravity on an object

• Attraction force between two masses

• Units forces are measured in

Multiple Choice

Mass is measured in...

• Newtons

• pounds

• grams

• kilograms

Multiple Choice

Weight is measured in...

• kilograms

• grams

• Newtons

• forces

Weight is calculated by the mass of an object, multiplied by the gravity being experienced.

Reorder

Rank the following from strongest to weakest gravitational field.

• Bus

• Dresser

• Stool

• Remote

• Tweezers

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

On Earth, gravity is 9.8 N/kg. An object with a mass of 20 kg would have a weight of 196 N.



weight = mass x gravity
196 = 20 x 9.8

Multiple Choice

What calculation would you put in your calculator to find the weight of a 85 kg object on Earth?

• 85 x 9.8

• 85 + 9.8

• 85 / 9.8

• 9.8 / 85

Convert mass to kilograms before calculating!

Match

Match the following masses to their mass in kilograms:

• 689 g

• 4780 g

• 2.5 tonnes

• 0.86 tonnes

0.689 kg

4.780 kg

2500 kg

860 kg

• 0.689 kg

• 4.780 kg

• 2500 kg

• 860 kg

Multiple Choice

What is the weight of a 476 mg object on Venus, with a gravity of 8.8 N/kg?

• 0.0042 N
• 350 N

• 4188 N

• 0.0035 N

The formula can be rearranged to calculate mass, and also gravity.

On Earth, gravity is 9.8 N/kg. What is the mass of an object with a weight of 250N?


weight = mass x gravity
250 = ? x 9.8
? = 250 / 9.8
? = 25.5 kg

Match

Calculate the weight for each object on Earth (gravity = 9.8 N/kg)

• 75N object

• 33N object

• 50N object

• 100N object

• 20N object

7.65 kg

3.36 kg

5.10 kg

10.20 kg

2.04 kg

• 7.65 kg

• 3.36 kg

• 5.10 kg

• 10.20 kg

• 2.04 kg

Copy and complete the table in your notebook.

​Check your answers on the next slide!

Check your learning, can you...

• ​explain the difference between mass and weight?

• state the units mass and weight are measured in?

• calculate the weight if given mass and gravity?

• calculate the mass if given weight and gravity?