The force is strong with you
a push or pull that acts on an object
force, p 220
friction, p222
a group of students is playing tug of war. Both teams are pulling on the rope but in opposite directions, and the rope's center is not moving. Are the forces balanced or unbalanced?
balanced
what is newtons second law
when an object is acted on by one or more unbalanced forces, the total net force is equal to the mass of the object times the resulting acceleration
this states that every object in the universe attracts every other object
Newton's law of universal gravitation 251
the si unit for force
newton (N), p220
why does friction occur
at the atomic level no surface is smooth, this roughness affects how closely molecules of different substances can get to one another. the closer molecules can nestle into one another and attract and adhere to each other. The more molecules adhere to each other, the more they will be able to resist motion and the stronger the frictional force between them will be, p223
this acts within the nucleus to hold it together
strong nuclear force
What is newtons 3rd law
for every action, there is an equal and opposite reaction
weight 243
What is the force of one newton?
the force required to make an object with a mass of 1kg accelerate at 1 m/s2
1N=1(kg x m)/s2
friction that opposes the initiation of motion
static friction, p224
a change in which of the following affects the weight of an object
air resistance, friction, acceleration due to gravity, velocity
acceleration due to gravity
Which of Newton's laws is sometimes called the law of inertia?
Newton's first law
mass x acceleration equals....
net force 237
what happens when an object has balanced forces acting upon it?
no change in the object's motion, 221
friction that opposes motion once the motion has already started
kinetic friction, p224
for every force there is a ________
reaction force
what is newton's first law
an object in motion (or at rest) will tend to stay in motion (or at rest) until an outside force acts upon it
what is the acceleration due to gravity near the surface of the earth
9.8 meters/s2 or 32 ft/s2 228
What happens when the net force on an object is not zero?
the object accelerates, p221
frictional force that acts on rolling objects
rolling friction
this force can both attract and repel
electromagnetic
inertia
yes, when air resistance is removed, all objects experience the same resistance to gravity