Motion Flashcards
Teach students important content on kinematics.
What is a scalar, and what scalars have we learned about?
A type of variable that only has magnitude (number value) and no direction. It can only be positive.
Types of scalars: Distance, Height, Speed, and Time
What is a vector, and what vectors have we learned about?
A type of variable that only has magnitude and direction. It can positive or negative.
Types of scalars: Displacement, Velocity, and Acceleration
What are the positive directions?
Positive x-axis, east, or right
Positive y-axis, north, or up
What are the negative directions?
Negative x-axis, west, or left
Negative y-axis, south, or down
What is distance?
A scalar quantity that refers tohow much ground an object has coveredduring its motion.
What is displacement?
Displacement- a vector quantity thatrefers tohow far your ending point is fromyour starting point
What is speed?
Speedis the ratio of distance and time (always positive) Scalar
average speed = distance traveled/ time or s=d/t
What is velocity?
Velocityis the ratio of displacement and time (can be + or -) vector
average velocity = displacement/ time, v =∆x/t
What is known about someone moving at a constant speed of 10 m/s,
Their speed doesn’t change.
They are not accelerating.
They move 10 meters every second.
Position vs time graphs provide what data?
The position of an object at specific times.
The slope of specific time intervals represents the object’s velocity.
On position time graphs, what does the slope represent?
Positive slope - is a positive velocity.
Negative slope - is a negative velocity.
A slope of 0 (horizontal line) - the object is not moving.
The steeper the slope the faster the object is moving.
The more horizontal the slope is the slower the object is moving.
What is the difference between instantaneous velocity and average velocity?
Instantaneous Velocity- the speed at any giveninstant intime. (Ex: Speedometer)
Average Velocity- the total displacementcovered over the totaltime. It can be used over many instances and is just an average. (Ex: GPS)
What is acceleration and what are the three ways an object can accelerate?
The change an object’s velocity (motion).
a = (Vf - Vo)/t
The three ways an object can accelerate is:
-speed up
-slow down
-change direction
How are acceleration and velocity related?
If the velocity is changing, the object is accelerating
If the velocity is staying the same (constant), the object is not accelerating.
Velocity vs time graphs provide what data?
Positive slope - is a positive acceleration.
Negative slope - is a negative acceleration.
A slope of 0 (horizontal line) - the object is not accelerating and the velocity is constant.
The steeper the slope the larger the acceleration.
The more horizontal the slope the smaller the acceleration.
When an object’s velocity and acceleration are going the same direction, what can be inferred?
-The object is speeding up
-The distance between time intervals is increasing.
When an object’s velocity and acceleration are going opposite directions, what can be inferred?
-The object is slowing down
-The distance between time intervals is decreasing.
When an object is not accelerating, what can be inferred?
-The object is either not moving or moving at a constant velocity.
The distance between time intervals is not changing.
What is accelerations definition equation?
a = (Vf -V0)/t
What is the kinematic equations that have the following variables?
a, t, Vf, and Vo
Vf =Vo + at
What is the kinematic equations that have the following variables?
a, t, Vo, and ∆x
∆x = Vot + 1/2at^2
What is the kinematic equations that have the following variables?
t, Vo, Vf, and ∆x
∆x = (Vf - Vo)/2 *t
What is parabolic motion?
Parabolic motion is the representation of projectiles move in the air.
How is the motion in the x - axis and y - axis related.
They are independent of each other. They do not affect one another.
What is the kinematic equations that have the following variables?
a, Vo, Vf, and ∆x
Vf^2 = Vo^2 + 2a∆x
What is the kinematic equations that have the following variables?
a, t, Vf, and ∆x
∆x = Vft - 1/2at^2
What is free-fall?
An object is in free fall when the only force acting on it is gravity.
ax = 0 m/s^2
ay = -9.8 m/s^2
When an object is in free fall and was thrown with an initial vertical velocity, what is its vertical velocity at the highest point?
At the highest point the vertical final velocity Vfy = 0 m/s
What is parabolic motion?
Parabolic motion is the representation of projectiles move in the air.
When a projectile is shot horizontally with an initial velocity of 10 m/s, what variables should you know?
x I y
ax = 0 m/s^2 I ay = -9.8 m/s^2
Vox = 10 m/s I Voy = 0 m/s
Whenever a variable is given at an angle θ, what is the first thing you should do?
Break up into the x- and y- components using the trig functions cos(θ) for x, and sin(θ) for y
When an object is shot with a initial velocity Vo at an angle θ, how do you solve for the x- component?
Vox= Vo cos (θ)
When an object is shot with a initial velocity Vo at an angle θ, how do you solve for the y- component?
Vox= Vo sin (θ)
What is the total velocity or speed, and how do do you solve for it?
The total velocity or speed is a combination of the velocity in the x- and y-axis.
V_total= √(Vx^2 + Vy^2 )
When an object is in projectile motion, what can be said about the velocity in the x- and y - axis?
x - axis : the velocity will not change
y - axis : the velocity will change
When an object is in projectile motion, what is known about the velocity at the same height in the x- and y - axis and when it is going up and down?
At same heights the velocity in the x - axis will always be the same, while the velocity in the y - axis will be the same magnitude but negative.
When an object is in projectile motion and returning to the same height, how is the total time related to the time to highest point?
The total time is twice as big as the time to highest point.
When an object is in projectile motion and returning to the same height, what is its vertical displacement?
∆y = 0 m
In projectile motion, which axis is used to solve for time?
y - axis
can only solve for time in the x-axis if the horizontal displacement (∆x) is known.
When an object travels up, what is the sign of vertical displacement (∆y)?
Positive because displacement is a vector and has direction.
When an object travels down, what is the sign of vertical displacement (∆y)?
Negative because displacement is a vector and has direction.
An airplane pilot is moving with a velocity v and drops a package. In the absence of air resistance, where is the package relative to the airplane the moment it hits the ground?
Directly below the plane because the are both moving at a constant velocity in the x-axis and not accelerating.
