# Force, Motion, and Energy

## Presentation on theme: "Force, Motion, and Energy"— Presentation transcript:

Force, Motion, and Energy
Newton’s Laws Speed, Velocity, Acceleration Gravity

Motion Motion occurs when an object changes its position.
Three Types of Motion: Relative Motion You v. solar system Distance How far something moves Displacement Difference between the end and the start NOT total distance

Speed Distance traveled per unit of time Speed = distance time
Example… You ran 2 km in 10 minutes. What was your speed?

Velocity Speed (a change in position over a period of time), but in a specific direction. Example: The cars at the Texas Motor Speedway drove a lap. They go 120 mph for 60 sec W,120 mph for 30 sec S,120 mph for 60 sec E, and 120 mph for 30 sec N. They had a direction which means they also had velocity.

Acceleration Acceleration occurs when an object changes its speed, direction, or both. Acceleration = change in velocity change in time When an object changes its direction or speed, it is accelerating.

Force A force is a push or a pull that one object applies to another.
A force can also cause an object’s motion to change. EX) Sports Balanced forces are equal in size and opposite in direction.

Inertia Inertia is the tendency of an object to resist any change in its motion. Objects with more mass have more inertia.

Newton’s First Law An object in motion tends to stay in motion and an object at rest tends to stay at rest until acted on by an outside force.

Force, Mass, Acceleration
For any object, the greater the force, the greater the acceleration. The acceleration of any object depends on its mass AND the force exerted on that object. KEY CONCEPT: Force, mass, and acceleration are connected.

Newton’s 2nd Law of Motion
Describes how force, mass, and acceleration are connected. REMEMBER: Net force = total forces acting on an object. States that the net force acting on an object causes the object to accelerate in the direction of the net force.

Newton’s 2nd Law of Motion
Acceleration of an object is determined by the size of the net force acting on the object and the mass of the object. So, the relationship between acceleration, net force, and mass can be defined as: F = ma

Friction If we give a skateboard a push, what happens?
But according to Newton’s 1st Law, what SHOULD happen? REMEMBER: When an object slows down, its velocity changes; if its velocity changes, it is accelerating. If an object is accelerating, a net force must be acting upon it.

Friction The force acting on the skateboard is friction. Friction is the force that opposes motion between 2 surfaces that are touching each other. The amount of friction between 2 surfaces depends on 2 factors: The kinds of surfaces. The force pressing the surfaces together.

Static Friction What does “static” mean?
Applied force is equal to the friction between the two surfaces.

Sliding Friction Applied force is greater than the friction between the two surfaces.

Rolling Friction The friction between a rolling object and the surface it rolls on. Rolling friction is usually much less than static or sliding friction. That is why it is easier to pull a load in a wagon rather than dragging it along the ground.

Friction Foldable Term Definition/ Example Picture Friction
Static Friction Sliding Friction Rolling Friction

Newton’s Third Law For every action, there is an equal and opposite reaction. Examples: Trampoline Rocket Propulsion