Lesson 7 — Gravity

• Force
• Middelbare school
• havo, vwo
• Leerjaar 1

1.4 Gravity

This lesson

• The science test 
• What is gravity?
• Mass, weight and gravitational field strength
• The formula for weight

Goals

•  Explain what gravity is in your own words.

• Define the concepts mass, weight and gravitational field strength.
  

•  Name and apply the formula to calculate weight.

The science test

What is gravity?

The Attractive force between any two object with mass.

Read paragraph 1.4

Write down a definition of the following words. Include their unit. 

• Mass
• Weight
• Gravitational field strength

Done — do the yellow block exercises of paragraph 1.4

two objects with a different mass

two situations where the same object has a different weight

two different gravitational field strength

Mass

• The amount of matter (stuff) something is made off (kg).
  

Weight

• The strength of the force of gravity on a specific object (N).

Gravitational field strength

• The amount of newtons a body of mass applies to other masses per kilogram (N/kg)
  

two objects with a different mass

two situations where the same object has a different weight

two different gravitational field strength

Gravitational field strength earth: 10 N/kg

Gravitational field strength earth: 10 N/kg

Gravitational field strength moon: 1.6 N/kg

The formula for weight

weight=mass⋅gravitationalfieldstrength

weight=mass⋅gravitationalfieldstrength

w=m⋅g

weight=mass⋅gravitationalfieldstrength

w=m⋅g

• w: weight (N)

• m: mass (kg)

• g: gravitational field strength (N/kg)

Exercise

Calculation Procedure

1. Given
2. Asked
3. Formula
4. Calculation
5. Check

Dave has a mass of 83 kg. The gravitational field strength on Earth is 9.8 N/kg. 

Calculate his weight on Earth.

Exercise

Calculation Procedure

1. Given
2. Asked
3. Formula
4. Calculation
5. Check

Dave turns out to be an astronaut! He will be traveling to Mars in the future. the gravitational field strength on Mars is 3.7 N/kg.

Calculate his weight no Mars.

Studying for the test

Goals

•  Explain what gravity is in your own words.

• Define the concepts mass, weight and gravitational field strength.
  

•  Name and apply the formula to calculate weight.