42 terms

# Conceptual Physics 04: Newton's Second Law

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

Equilibrium
In general, a state of balance where Fnet = 0
Force
Any influence that tends to accelerate an object. A push or a pull; measured in Newtons.
Friction
The force that acts to resist the relative motion (or attempted motion) of objects or materials that are in contact. A force that works against the motion of an object
Kilogram
The fundamental SI unit of Mass.
Mass
A measure of an object's inertia. Also, a measure of the amount of matter in an object. Depends only on the amount of and kind of particles that compose an object - not on its location.
Newton
SI Unit of Force.
Normal Force
For an object at rest, it is the upward force that balances the weight of the object at rest. Also called a Support Force
Support Force
For an object at rest, it is the upward force that balances the weight of the object at rest. Also called a Normal Force
Weight
The force on a body due to the gravitational attraction of another body (commonly the Earth). (*a downward force!*)
Volume
The quantity of space an object occupies
Newton's Second Law
The acceleration of an object is directly proportional to the net force acting on the object, it in the direction of the net force and is inversely proportional to the mass of the object. In other words... F=ma
Free Fall
Motion under the influence of gravitational pull only
Terminal Speed/Velocity
The speed at which the acceleration of a falling object terminates because air resistance balances its weight.
Acceleration
Change in velocity divided by the time it takes for the change to occur
Inverse Proportion
a relation between two quantities such that one increases in proportion as the other decreases.
Direct Proportion
A relationship between two quantities in which one increases as the other increases
Air Resistance
frictional force air exerts on a moving object; acts opposite in direction to the object's motion.
Depends on two things: speed and frontal surface area
Net Force
The sum of all forces acting on an object. It is the net force that accelerates a mass (in the direction of the net force).
If an object is accelerating to the right, which direction must the friction point
Left
The acceleration of an object is affected by which two forces?
Mass and net force
A 2kg object has an acceleration of 8m/s2.... What must be the net force acting on it?
16N
An unbalanced force is also known as a
Net force
If an object is being pushed and its mass increases, then its acceleration must
Decreases
If the net force applied to an object increases. Then its acceleration will
Increases
A 5kg suitcase falls out of a plane. When 50N of air resistance acts on it, what is its Fnet?
0N
If the forces of an object are unbalanced, what kind of motion must it have?
Changing motion
A girl pulls her brother on a sled with a net force of 60N. What happened to its motion?
It speeds up
The boy gives a box a big push and then lets go. Friction acts against it. What's happening
It slows down
Which of the following affect Air Resistance on an object
Speed and frontal surface area
An object moves along a straight path. If the net force on it doubled, its acceleration would
Double
Whenever the net force on an object is zero, its acceleration
Is 0m/s2
Slide a book on its widest surface then, on its narrowest surface. Where is the friction greater?
Both same
What's the acceleration of a 10,000 kg jet that's being acted upon with 20,000 N of force
2m/s2
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration
decreases
Net force and acceleration are
directly proportional
Which is normally greater: static friction or sliding friction on the same object?
static friction
What is the weight of a 10kg object on earth
100N
What is the mass of a 60kg object on the moon
60kg
What is the weight of 500 grams of bananas
5,000 N
Acceleration is inversely proportional to
mass
Force equals
mass x acceleration
Weight equation
mass x gravity