Contact Forces
a push or pull on one object by another object that is touching
contact force
A force that one object can apply to another object w/o touching
noncontact force
The combination of all the forces acting on an object
Net force
prevents surfaces from sliding past each other
static friction
Explain the difference between a contact and noncontact force.
contact- touching
noncontact- non touching
List the types of contact forces
applied, friction, normal
the force exerted by magnets when they repel or attract one another
magnetism
How do you calculate net force of objects moving in same directions?
find the sum of the forces
The support force exerted on an object that touches another stable object
normal force
What's the difference between a balanced and unbalanced force?
Balanced forces: forces acting on an object that combine and form a net force of zero
Unbalanced forces: forces acting on an object that combine to form a net force that is not zero
How can friction be reduced? Give one example.
lubricant ex. soap/oil
an attractive force that exists between all objects that have mass
gravity
What two things do arrows tell us?
Length = magnitude
Direction = direction
distance and mass
mass increases, gravity increases
Which force best describes what happens when a hockey puck comes to a stop on a driveway instead of going into a goal.
friction
How does distance affect gravity?
distance increases, gravity decreases
How do you calculate net force of objects moving in opposite directions?
sum of positive and negative forces
How do non moving objects have forces acting on them?
normal force
Which force best describes what happens when a hockey puck comes to a stop on a driveway instead of going into a goal.
friction
Which force best describes what happens when a boy wipes a table off with a washcloth, moving the washcloth at a constant speed across the table?
applied force
What two things does magnetism do for us?
compass points north
Protects us from harmful sun particles
How can net force be zero?
equal forces act on same object in opposite directions, motion doesn’t change
How does an object move when pushed?
if applied force is greater than sliding friction
All objects are attracted to each other by gravity
law of universal gravitation