L11;C10

Question 1

What are kinematics?

Answer 1

These are descriptions of motion without regard to its cause or effect. It’s the spatial and temporal frame of reference.

Question 2

What is the description of general motion? What is it comprised of?

Answer 2

General motion is comprised of linear and angular components.

Question 3

Motion is the change in position with respect to both ______ and _______ frames of reference

Answer 3

Spatial (relative to point in space) and temporal (relative to time)

Question 4

Give a description of the following terms:

Displacement
Velocity
Acceleration

Answer 4

Displacement= change from initial position to final (spatial quantity) 
Velocity= change from position relative to time interval that has occurred 
Acceleration= change in velocity relative to the interval of that change

Question 5

Give me the formulas for:

Displacement:
Velocity:
Acceleration:

Answer 5

Displacement= Δp=p2-p1

Velocity= ΔV=distance/time

Acceleration= Δa= ΔV/ΔT

Question 6

What is linear displacements? What do these must include? What kind of quantity are displacements?

Answer 6

Linear displacements are straight lines that connect an objects position from one instant in time to another

These must include both the length and direction of the line and measure in cm, mm, km etc

These are a vector quantity

Question 7

What are linear distances? What kind of quantity are they? What are they measured in?

Answer 7

Linear distances are the total length of the path travelled by an object. Distance does not have an associated direction. These were a scalar quantity and measured in mm, cm, km, etc.

Question 8

What is linear velocity? What kind of quantity is it? What is it measured in?

Answer 8

Linear velocity is the change in position over the change in time (ΔP/ΔT)
This is basically how fast displacement changes. This is a vector quantity and magnitude and direction are specified. Measured in m/s, km/h, etc

Question 9

What is linear acceleration? What kind of quantity is it? What’s it measured in?

Answer 9

Linear acceleration is the change in linear velocity divided by given time. (ΔV2-V1/ΔT) This has direction and magnitude. This is a vector quantity and is measured in m/s, km/h, etc.

Question 10

What is linear speed?

Answer 10

This is the change in distance traveled over a given time frame ΔT=T2-T1
- there is no direction associated with this

Question 11

What does it mean when acceleration is zero?

Answer 11

This means an objects velocity is constant because if:

A= ΔV/ΔT then ΔV must = 0

Question 12

What does constant velocity mean?

Answer 12

This means that an object is traveling at a constant speed and IN THE SAME direction

Question 13

If direction changes, we still have __________

Answer 13

Acceleration

Question 14

What happens if acceleration is constant?

Answer 14

This means an objects velocity is linearly increasing or decreasing
- acceleration cannot be zero because velocity is changing

Question 15

At peak displacement (apex) what is velocity of a ball and acceleration?

Answer 15

Velocity= 0
Acceleration= -9.81m/s

Question 16

What are the three things projectile trajectory is influenced by?

Answer 16

1. Gravity
2. Air resistance
3. Projectile parameters (angle, height, speed)

Question 17

How does gravity influence trajectory?

Answer 17

• only affects vertical motion

- accelerates objects down towards the centre of the earth at -9.81m/s

Question 18

How does air resistance influence trajectory?

Answer 18

• affects horizontal motion of trajectory

- when neglected, horizontal speed is constant

Question 19

How does the angle fo projection influence trajectory? What is the optimal mechanical angle?

Answer 19

• the angle dictates the shape when projection height and speed are constant
• optimal angle is 45 degrees mechanically for range

Question 20

How does sped influence the projectiles trajectory?

Answer 20

• when other parameters are held constant, projection speed determines trajectory size/length

for vertical projectile angles= projection speed determines max vertical displacement

for oblique projectile angles= projection speed dictates vertical horizontal displacement

Question 21

If velocity 2 is greater than velocity 1, acceleration is ______
If velocity 2 is smaller than velocity 1, acceleration is ______

Answer 21

Positive, negative