Position-Time Graphs
Which of the following can you not obtain from a position-time graph? position, time, velocity, mass
mass
Vectors have magnitude and _______.
direction
What is the difference between Δx and Δy?
x is horizontal, y is vertical
At maximum height, the vertical velocity is _____.
zero
Velocity is change in _____.
position
The slope of a position-time graph tells you __________. For instance, a negative slope means negative ______________.
velocity
Give an example of a vector. Double points for naming more than one example.
Displacement, velocity, and acceleration
What is the symbol for final velocity?
vf
Without air resistance, which object reaches the ground first: a bowling ball or a feather?
If there is no air resistance, they reach the ground in the same amount of time.
If an object is speeding up, then what does that mean about the signs (+ or -) of acceleration and velocity?
The more curved a line on a position-time graph, the greater its _____.
acceleration
Distance, speed, mass, time
The phrase "dropped from rest" means we know one of the variables. Which variable is it?
vi = 0
What is the acceleration due to gravity?
-9.8 m/s2 (-10 m/s2)
Acceleration is change in _______________.
position
If a line is curved on a position-time graph, then that means that the motion is _____.
accelerated
-9 m/s is an example of a scalar or vector? How do you know?
Vector because it has a negative sign indicating direction. Scalars don't have direction.
What are the units of acceleration?
m/s2
If an object is thrown upward at +3 m/s and is caught at the same height, then what is the final velocity?
-3 m/s
Acceleration is when an object _______, ________, or _________.
speeds up, slows down, changes direction
Draw a position-time graph for an object that is in uniform accelerated motion with positive initial velocity and negative final velocity. Double points for accurately labelling the axes with appropriate units.
Any graph that is curved like an upside-down U.
Vectors are represented by which shape that shows both magnitude and direction?
an arrow
What is the symbol for displacement (or change in position)?
Δx
If acceleration due to gravity is roughly -10 m/s2, then how many seconds does it take a ball dropped from rest to reach -20 m/s?
(hint: each second, the ball goes 10 m/s faster in the negative direction)
2 seconds
An object traveling at 3 m/s slows to a stop in 9 m. Which equation do you use to find out the acceleration? Double points if you correctly predict (without calculating) whether the sign of the acceleration is negative or positive.
The equation with vf2