36 terms

# Physical Science Motion and Force ch 12

Force and motion vocabulary

#### Terms in this set (...)

Force
a pull or push
Net force
The combination of forces acting on an object at any given point.
Newtons 1st Law
Objects at rest tend to stay at rest and objects in motion tend to stay in motion unless acted on by a force
Newton's 2nd law
The acceleration of an object is in the same direction as the net force acting on the object.
Gravity
An attractive force between any two objects that depends on the masses of the objects and the distance between them.
Weight
The gravitational force exerted on an object on Earth's surface.
Newton's 3rd law
States: to every action there is an equal and opposite reaction.
Momentum
The product of objects mass and velocity.
Acceleration is "________________" to mass
inversely proportional
Acceleration is "_________________" to force
directly proportiona
Acceleration due to gravity
9.8 m/s2
The equal and opposite forces are called
⇒ action and reaction forces
Law of Conservation of Momentum
If no external force acts on a closed system of objects, the momentum of the closed system remains constant
Electromagnetic Force
Act between charged objects or subatomic particles
Magnetic force
Act on certain metals, poles of magnets, and on moving charges
Strong Nuclear Force
Holds together the protons and neutrons of the nucleus
Strong Nuclear Force
Strongest universal force, acts over the shortest distance
Weak Nuclear Force
Affects all subatomic particles in the nucleus of an atom, not just protons and neutrons
Gravitational Force
Force that depends on mass and distance
Force can accelerate a moving object by changing its:
Speed, direction, or both
Gravitational Force
Weakest universal force, but it is the most effective force over long distances.
Objects with like charges ________ each other
repel
Objects with opposite charges ________ each other
attract
Electric and Magnetic
The only two forces that can both attract and repel.
The Four Universal Forces
Electromagnetic, Strong Nuclear, Weak Nuclear, Graviational
units for momentum
kg•m/s
Forces always exists in
Pairs.
Your in-line skates are sitting in a box on a shelf in the closet. What
is their momentum?
Zero
According to the law of conservation of momentum, what happens to the total momentum of a system if no net force acts on the system?
The total momentum does not change.
Inertia
tendency of an object to resist a change in its motion.
Earth's gravity acts in a ________ direction
Downward
When __________ forces act on an object net force is zerio
Balanced
The friction force that acts on objects that are at rest is _________.
Static
Friction force opposing motion of an object moving through fluid
Fluid
Friction force that opposes the motion of objects sliding.
Sliding
Unit of measure for force.
Newtons

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