Chapter 1: Matter in Motion Flashcards
motion
an object that changes position over time relative to a reference point
reference point
the object that appears to stay in place
speed
the distance traveled by an object over a certain period of time (distance/time)
formula to determine average speed
=total distance/total time
velocity
speed with reference to the direction (ex. 600 km/h south)
change in velocity
occurs if either change in speed or direction
resultant velocity
occurs when you combine two velocities (example: you walk up the aisle of a moving bus; bus velocity + your walking velocity = resultant velocity
acceleration
rate in which velocity change; if an object’s direction or velocity change it is accelerating
negative acceleration
deceleration
average acceleration
= final velocity-beginning velocity / time
force
a push or pull
newton (N)
unit of force
net force
combination of all forces acting on an object
forces in different directions (how to find net force)
subtract the two forces
forces in the same direction (how to find net force)
add the two forces
balanced forces
net forces = 0 N
friction
a force that opposes motion between two surfaces that are in contact with each other
effect of friction
the rougher the surface the more friction
kinetic friction
kinetic means “moving”, friction between moving surfaces
static friction
“not moving”, friction is applied by the object doesn’t move
lubricants
substances applied to surfaces to reduce friction (WD-40, wax)
gravity
force of attraction between two objects due to their masses
how mass affects gravitational force
the larger the mass, the greater the gravitational force
how distance affects gravitational force
the greater the distance, the less affect of gravity
