Chapter 2: Motion Along A Straight Line

Question 1

What is the purpose of kinematics?

Answer 1

Describing motion without addressing the cause of that motion. It is limited to the study of motion of particles.

Question 2

What is a particle?

Answer 2

Any object in which every part of that object moves exactly the same way at any instant.

Question 3

What is position?

Answer 3

A coordinate on a chosen axis, relative to a chosen origin.
SI unit: meter (m)
Symbol: x, y, z

Question 4

Is position a vector quantity?

Answer 4

Yes!

Question 5

What is average velocity?

Answer 5

The rate of change of position over a finite time interval–OR displacement divided by a time interval.
SI unit: m/s
Symbol (for x-axis motion): v(avg) = (Δx)/(Δt)

Question 6

Is velocity a vector quantity?

Answer 6

Yes!

Question 7

What is displacement?

Answer 7

The total change in position between two points.
SI unit: meter (m)
Symbols: Δx, Δy, Δz

Question 8

Is displacement a vector quantity?

Answer 8

Yes!

Question 9

What is instantaneous velocity?

Answer 9

Velocity at a specific instant in time.
SI unit: m/s
symbol (motion along an x-axis): v = dx/dt

Question 10

What is average acceleration?

Answer 10

The rate of change of velocity over a finite time interval.
SI unit: m/s^2
Symbol: a(avg) = Δv/Δt

Question 11

Is acceleration a vector quantity?

Answer 11

Yes!

Question 12

What is instantaneous acceleration?

Answer 12

Acceleration at a specific instant in time.
SI unit: m/s^2
Symbol: a = dv/dt

Question 13

If acceleration and velocity have the same sign, the particle is ___ while moving in the direction of the velocity!

Answer 13

Speeding up

Question 14

If acceleration and velocity have opposite signs, the particle is ___ while moving in the direction of the velocity!

Answer 14

Slowing down

Question 15

What is free-fall motion?

Answer 15

Any motion of a particle under the influence of gravity alone.

Question 16

All objects in free-fall near a planet’s surface have the same constant ___, independent of the object’s mass.

Answer 16

Acceleration

Question 17

Acceleration due to gravity is directed ___.

Answer 17

Vertically down

Question 18

On Earth, this acceleration has magnitude g, or ___.

Answer 18

9.8 m/s^2

Question 19

Integrating acceleration gives change in ___. Conversely, the derivative of ___ gives acceleration.

Answer 19

Velocity; velocity.

Question 20

Integrating velocity gives change in ___. Conversely, the derivative of ___ gives velocity.

Answer 20

Position; position.

Question 21

The three key acceleration equations:

Answer 21

v =(v0)+at
x=(x0)+(v0)t+(1/2)at^2
v^2=(v0)^2+2aΔx