Describing Motion
Occurs when an object changes position relative to a reference point
The speed of an object and the direction of its motion
What is velocity?
a push or pull on an object
what is force?
the law of inertia
gravity depends on the ______ and _________ between objects
mass and distance
The formula for calculating speed
distance divided by time
acceleration
John Cena pulls the ladder with 10 N of force. Rey Mysterio pulls the ladder with him adding 5 N of force. What is the net force on the ladder?
15 N
tendency of an object to resist any change in its motion
inertia
gravitational force exerted on an object, measured in newtons
weight
What are the three types of speed we discussed?
instantaneous, average, constant
change in velocity divided by time
(final velocity minus initial velocity) divided by time
A plane is flying at a constant speed. The net force is 0, and the forces are _________
balanced
The pitcher throwing the ball towards the batter at home plate demonstrates what law of motion
2nd
A projectile follows a curved path and has ____ and ____
horizontal and vertical motion
The difference between distance and displacement
Distance is how far an object has traveled. Displacement is the distance and direction of an object's change in position from a starting point.
What is the difference between positive and negative acceleration? give an example of each
Positive acceleration is speeding up, like a plane taking off.
Negative acceleration is slowing down or stopping, like stopping at a stop sign.
A friction like force that opposes motion of objects that move through air
air resistance
A baseball bat making contact with the baseball demonstrates what law of motion
3rd
the greater the _________ the _________ the gravitational force on the obejct
mass; stronger
Describe how motion can be plotted on a graph
Motion can be graphed with time on the X-axis and distance on the Y-axis. The slop of the line gives the speed of the object in motion
2A paperboy rode his bike at 3 m/s.
After being chased by a dog for 8 seconds, he was traveling 6 m/s.
What is his acceleration?
(6 m/s - 3 m/s) / 8 s
(3 m/s) / 8 s
0.375 m/s2
What are the 4 types of friction and an example of each?
static - book sitting on a table
sliding - rubbing hands together
rolling - tires rotating as you drive
fluid - skydiving
The reason your body jolts forward when the car comes to an abrupt stop.
calculated by mass times velocity
momentum
centripetal means
towards the center