Physics

PhysicsEnergy and matter interact through forces that result in changes in motion.

Objective

• Describe different patterns of motion of objects.

Motion is Relative• The motion of an

object is always judged with respect to some other object or point. The idea of absolute motion or rest is misleading.

Speed and Velocity• The motion of an

object can be described by its position, direction of motion, and speed.

Net Force• An object’s motion is the result of the

combined effect of all forces acting on the object.

Newton’s First Law• A moving object that

is not subjected to a force will continue to move at a constant speed in a straight line.

• An object at rest will remain at rest.

Newton’s First Law

Newton’s Second Law• Force is directly

related to an object’s mass and acceleration.

• The greater the force, the greater the change in motion.

Newton’s Second Law

Newton’s Third Law• For every action there is an equal and

opposite reaction

Objective

• Observe, describe, and compare effects of forces (gravity, electric current, and magnetism) on the motion of objects.

Gravity• Every object exerts

gravitational force on every other object.

Gravity• Gravitational force depends

on:• mass of the objects • how far apart the objects are

Gravity• Gravitational force depends

on:• mass of the objects • how far apart the objects are

Gravity• Gravitational force

depends on:• mass of the objects • how far apart the

objects are

Orbit• Gravity is one of the forces acting on orbiting

objects

Projectile Motion• Gravity is one of the

forces acting projectiles.

Electromagnetism• Electric currents and magnets can exert a

force on each other.

Machines• Machines transfer mechanical energy from one

object to another.

Friction• Friction is a force that

opposes motion.

FRICTION

Lubricants• A machine can be

made more efficient by reducing friction. • Some common ways

of reducing friction include lubricating or waxing surfaces.

Machines Make Work Easier• Machines can change:• the direction • amount of force • the distance or speed of force required to do work.

Machines Make Work Easier

Simple Machines• Simple machines include a lever, a pulley,

a wheel and axle, and an inclined plane.

Complex Machine• A complex machine uses a

combination of interacting simple machines, example: a bicycle.