Newton’s 2 nd Law

Chapter 8

Newton’s 2nd Law

• Newton’s 2nd Law of Motion- an unbalanced force accelerates an object in the direction of that force

Newton’s 2nd Continued

• The larger the force, the greater the acceleration

• The larger the mass of the object, the larger the force needed to produce acceleration

Formula

• Formula for Newton’s 2nd Law:Force = Mass x Acceleration

or

F=MA

Force is measured in Newtons

1 Newton = 1 Kg x m/s2

Gravity and Newton’s 2nd

• Gravity- on Earth has acceleration of 9.8 m/s2

– So to find the force you are being pulled you take your mass multiplied by 9.8 m/s2

– Force Earth pulls on you = mass x (9.8m/s2)

Weight vs. Mass• Your mass does not change when you go to

a different planet, it stays the same• Your weight does change…this is because

your weight depends on the amount of acceleration due to gravity of the different planets.

So why does this happen?

Examples of Newton’s 2nd in action

• Moving a piano- 1 vs. 2 people• Moving a bookcase with/without books.• Gas Mileage- Large vs. small vehicle• Sledding- Father pushes son vs. son

pushes father• Race cars- Light bodies, powerful

engines, aerodynamics