# Force 6 th Grade Test Monday. Forces affect Motion in Predictable Ways Newton’s Laws 1 st Law: Law of Inertia 2 nd Law: F=ma 3 rd Law: Action Reaction.

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Force 6 th Grade Test Monday

Forces affect Motion in Predictable Ways Newton’s Laws 1 st Law: Law of Inertia 2 nd Law: F=ma 3 rd Law: Action Reaction Law Link To Newton’s 3 Law Review

Some Types of Forces Gravity Friction Weight Thrust Lift Drag Magnetism

Force A force is defined as an action on an object that affects its motion (or lack of motion). The action is often called a push or pull. The push can come from direct contact, like when objects collide or from a force field like magnetism. The pull seems to only come from a field at a distance, like gravity or magnetism. The action from a force can cause an object to move or speed up (accelerate), to slow down (decelerate), to stop, or to change direction. Since any change in velocity is considered acceleration, it can be said that a force on an object results in the acceleration of an object.

Thrust Thrust is a force induced in the direction of flight. It opposes the drag force. To continue moving, an object must generate enough thrust to equal the drag forces on it. To accelerate, the thrust must exceed the drag. Examples: engines, air from hover craft, flapping of wings Uses Newton’s 3 rd Law Propulsion Page Four principal propulsion systems: the propeller, the turbine (or jet) engine, the ramjet, and the rocket.propeller,turbine (or jet) ramjet,rocket.

Harrier Aircraft can change direction of thrust

Weight Weight is a force that is caused by the pull of gravity and is always directed towards the center of Earth (at least if you are near Earth). Measured on a scale. Weight is different from mass. Mass is the amount of matter (or stuff) something is made of. Measured on a balance (triple beam balance).

Lift Lift is the force opposing the weight of the object. An aerodynamic force. It always acts perpendicular to a flying object. In a boat, it acts perpendicular to the wind direction. Examples: wings of airplanes, gliders and birds, parachutes, and sail of a boat

Drag Drag is the force that opposes the direction of movement. In a boat it works parallel to the wind direction. Something that slows the movement of an object.

Gliders Lift Drag Weight NO THRUST

Friction Friction is a force that resists motion between two touching surfaces. It always acts opposite to the direction of the motion.

Magnetism Magnetism is a force of attraction or repulsion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles or is inherent in magnetic objects such as a magnet. A magnet is an object that exhibits a strong magnetic field and will attract materials like iron to it. Magnets have two poles, called the north (N) and south (S) poles. Two magnets will be attracted by their opposite poles, and each will repel the like pole of the other magnet.

Maglev Train

Force and Motion in Action Airplanes Rockets Cars Sports Boats Maglev Train

Formulas and Force Speed = distance / time s=d/t Acceleration = (final Speed – initial Speed)/time a=(s f -s i )/t Force = mass x acceleration f=ma