Chapter 4 Flashcards
(28 cards)
Newton’s First Law
an object in motion stays in motion, an object at rest stays at rest
What is natural state
a constant state of velocity
A force is what
a push or a pull, is a vector with magnitude and direction, can be close up or far away, requires a agent to do the pushing or pulling
know how to draw a force vector
draw a force vector as an arrow pointing in the direction the force acts, give vector a label like F, place tail of vector on the object
how do you find net force
f1+f2+f3…. keep adding forces. BUT YOU NEED TO BREAK INTO COMPONENTS TO ADD!!!
what is weight
the gravitational pull of earth on an object. THIS IS ALWAYS POINTING VERTICALLY DOWNWARD. symbol is W or w
A spring does what when it’s compressed or stretched out
a stretched spring exerts a pulling force on an object. a compressed spring exerts a pushing force on an object. symbol is f and sp on the bottom
Tension exerts a force where
always in the direction of the string or rope. it’s only a pulling force. symbol is T
Normal force example and what it can be
symbol is n. it’s literally the pressure your body applies when laying or sitting on something or an object. the arrow goes perpendicular to where the weight is. if a book is lying on something the arrow is up.
Friction is
It is an interaction of atoms between surface and object, always parallel to the surface.
kinetic friction
symbol is F and k on the bottom, acts when an object slides across a surface, points in the opposite direction of the objects motion
static friction
symbol is f and s on the bottom, the force that keeps an object stuck on a surface and prevents it’s motion, points in the direction necessary to PREVENT motion
Drag
Friction due to air, water, etc. It is opposite to the direction of motion, symbol is D, do not include any time of air resistance or drag unless a problem explicitly says so
Thrust
force from an engine that pushes an object, always points up, symbol is Fthrust, opposite direction of where the exhaust gas is dispelled,
Say all 9 forces you know and symbols
weight, general force, spring force, tension, normal force, static friction, kinetic friction, drag, thrust
how to draw and identify forces
identify the object of interest and put a circle around them, locate every point where other objects are touching the point of interest, name and label short range and long range forces
Force and motion. What causes constant acceleration when concerning forces
an object pulled at a constant force will cause a constant change in velocity
What is inertia
the tendency to resist a change in velocity, car has more inertia than a bike
Mass is
the quantitative measure of inertia. the amount of matter in an object
acceleration formula
Force divided by mass. Or if there are multiple forces it’s fnet or to find force you can say F equals mass times acceleration
SI units for force formula
kg.m/s2. because acceleration is meters per second squared and we’re looking at mass in kilograms.
Newtons second law is
the force and acceleration formula. it is called the law of nature
when the force equation equals one it’s called
1 Newton. 1N.
1 pound equals
4.45 N
