One Dimensional Motion Physics Practice

Neglecting air resistance.  Any mass would take the same time to hit the ground no matter how massive or minute.  Many times a question may say in a vacuum which means there is no air resistance since air particles are sucked out removed from a vacuum.

Slope of a velocity time graph is acceleration.  Either find the slope or turn it into an equations picking givens off the graph (either way you are doing the same thing)

Went from 16 meters to 8 meters (backwards 8 meters) in 30 seconds. The slope on a position or displacement time graph is equal to velocity

Constant velocity backwards

On a V/T graphs the slope is acceleration.  The slope here is sloped so there is acceleration.  Another way to think about it is by what is happening in the graph.  The object went 0 m/s to 12 m/s during the 30 seconds.  They sped up during the entire time.

On a V/T graphs the slope is acceleration.  The slope here is flat so no acceleration but it does have a constant velocity of 8 m/s the entire time.  Another way to think about it is by what is happening in the graph.  The object went 8 m/s and kept going 8 m/s for 30 seconds.  Therefore moves 8 meters more every second for 30 seconds.

On a P/T graphs the slope is velocity.  The slope here is flat so no velocity.  Another way to think about it is by what is happening in the graph.  The object went from 16 meters to 16 meters in 30 seconds.  Therefore is in the same place and did not move.

The acceleration is always 9.8 m/s² down or averaged to 10 m/s² down.

The ball dropped would have a head start and always be traveling faster downwards

The acceleration is always 9.8 m/s² down or averaged to 10 m/s² down

It does not matter what happened to get it there.  Thrown up, dropped, or thrown down they all have different velocities but those velocities change by 9.8 m/s² down

The Y velocity continues to change but is 0 m/s at the top of the flight for an instant.

The acceleration is always 9.8 m/s² down or averaged to 10 m/s² down anywhere in flight but the velocity does change in the Y axis and is 0 m/s at the top

variable: unit (unit variable)

x : meters (m)

v, v_i, v_f : meters/second (m/s)

a: meters/second² (m/s²)

t: (s)

v = (Δx)/t

The change in displacement over time is the definition of velocity.  See the equation above

north is the direction the 15 m is pointing

The unit defines what the 15 is.  15 what?

meters

• What is your velocity after going 10 meters east followed by 20 meters west in 10 seconds?
• Velocity is a vector so direction matters so displacement divided by time.  Make the directions into signs.
• 10 m east is  +10
• 20 m west is -20
• now calculate displacement and divide that by time ((+10)+(-20))/10
• -10/10 = -1 m/s
• turn the negative back into a direction 1 m/s west

What is your speed after going 10 meters east followed by 20 meters west in 10 seconds?

speed is a scalar so disregard the direction.

v = x/t

(10 meters + 20 meters) / (10 seconds)

15 m is a magnitude and east is a direction.  This is the vector displacement having both magnitude and direction from the origin to the end.

Distance is a scalar that has no direction. You do nothing with the direction and just add all the individual magnitudes up (10 + 3) here.

You can't put a direction on the final answer since it is a measure of how far you went totally and not a direction.

You should not put a direction on the final answer either since this is not a measure of where you are located but just how far you went in any direction.