Lesson 7

• Physics
• Middelbare school
• vwo
• Leerjaar 3

Chapter 2 Forces

Section 3 Driving forces and resisting forces

This Lesson

• Discussing exercises
• Newtons first law
• Air resistance

Discussing section 2

exercise 5 and 6

Practice exercise

On an experimental setup on the moon a weight with a mass of 5 kilogram is hung on a spring with a spring constant of 0,45 N/m. Calculate the extension of this spring.

Voyager 2

Link

Newtons first law

If the resultant force of all the forces is zero (0N), the object is either stationary or it moves along a straight line at a constant speed

Air resistance

F​r,a​​=​2​​1​​C​d​​⋅ρ⋅A⋅v​2​​

• F_r,a: Force, resistance, air resistance (n)
  
• C: resistance coefficient (no unit)
• ρ: The density of air (or whatever medium the object is traveling through) (kg/m³)
• A: area of the object (m²)
• v: the speed of object (m/s)