Forces How Do Forces Affect motion?
Force • A push or a pull • Force can cause an object to change speed or direction • A Force is measured in Newtons • 1 N =1 kg x 1 m/s2 • Force = Mass x acceleration • Newton’s 2nd law
Net Force • Combination of all forces acting on the object • Forces acting in the same direction: add together
Unbalanced Force • Unbalanced force causes a change in the objects motion. Net force is NOT 0 Newtons
Balanced Force • Net force is 0 Newtons
Newton’s Second law • The acceleration of an object depends on the mass of an object and the amount of force applied. • F=ma • F= force; m= mass (kg); a= acceleration (km/s2) • What is the force? 24 kg x 40 m/s2 =N
Newton’s 1st law • Law of inertia • An object at rest stays at rest, an object in motion stays in motion at the same speed unless, acted upon by an unbalanced force.
Newton’s third law • Whenever an object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
Newton’s 3rd law • Forces in pairs have equal size but opposite directions