kinematics - Unit 1

Question 1

What are the two basic types of quantities?

Answer 1

Scalars and vectors quantities.

Question 2

What is a scalar quantity?

Answer 2

A scalar quantity only has a magnitude (just another way to say size), no direction needed.

Question 3

what is a vector quantity?

Answer 3

A vector quantity has a magnitude/size and a direction.

For representing vector quantities, use an arrow above symbols.

Question 4

What is a POSITION vector and what does it need?

Answer 4

A position vector locates an object. It starts at the origin (the starting point) and points to the location of the object.

A position vector = magnitude + direction + reference point

Question 5

What units are used to measure distance and displacement?

Answer 5

Distance and displacement are measured in metres (m).

Question 6

What is distance?

Answer 6

Distance is the total movement of an object and is a scalar vector, so no direction needed.

Question 7

What is displacement?

Answer 7

Displacement is the change in magnitude/size and direction of an object and is a vector, so direction needed.

Final answer must be stated with magnitude and direction.

Question 8

What is the formula for displacement?

Answer 8

∆d = d_f - d_i

*all with an arrow on top of it because displacement is a vector.

Question 9

What is the formula for the total displacement?

Answer 9

∆d_t = ∆d₁ + ∆d₂ + ∆d₃ + …

*For displacement add arrow on top because it is a vector and beware of directions !!

Question 10

What is speed?

Answer 10

Speed is the rate of change of distance.

v = ∆d / t

Question 11

What is velocity?

Answer 11

Velocity is the rate of change of displacement.

v = ∆d / t

A vector = an arrow on top of it

Question 12

Convert km/h ➝ m/s

Answer 12

Divide by 3.6

Question 13

Convert m/s ➝ km/h

Answer 13

Multiple by 3.6

Question 14

What is a position-time graph constructed of and state units?

Answer 14

Position-time graphs are constructed if you have a position (metres) and time (seconds).

Question 15

What does a positive slope indicate on a position-time graph?

Answer 15

A positive slope indicates a positive velocity and that the object is going forward.

Question 16

What does a negative slope indicate in a position-time graph?

Answer 16

A negative slope indicates a negative velocity and that the object is going backwards (towards its starting point) on a position-time graph.

Question 17

What does a linear line represent on a position-time graph?

Answer 17

A linear line on a position-time graph represents a constant velocity.

Question 18

What is the slope equation?

Answer 18

y𝟐 - y𝟏 / x𝟐 - x𝟏

Question 19

How to represent a constant velocity on a velocity-time graph?

Answer 19

A horizontal line on a velocity-time graph represents a constant velocity on a velocity-time graph.

Question 20

How to get the displacement of an object from a velocity-time graph?

Answer 20

The area underneath of a velocity-time graph gives the displacement of the object.

area of rectangle= l x w
area of triangle = 1/2 b x h

Question 21

What does relative velocity depend on?

Answer 21

Relative velocity depends on the frame of reference.

Question 22

When two objects are moving away from each other what would you do to get the relative velocity and the directions?

Answer 22

Subtract and both heading in a positive direction.

Question 23

When two objects are moving towards each other what would you do to get the relative velocity and the directions?

Answer 23

Add. A negative direction and positive direction

Question 24

What does acceleration mean?

Answer 24

Acceleration is how quickly the velocity is changing and is the rate of change of velocity.

Question 25

What is the formula for acceleration? What must it must as well?

Answer 25

The formula for acceleration is a = v𝐟 - v𝐢/ t It must have a direction because it is a vector.

Question 26

If the initial velocity and the acceleration have the same sign (either both positive or both negative) the object is …?

Answer 26

The object is speeding up

Question 27

If the initial velocity and the acceleration have opposite signs the object is …?

Answer 27

The object is slowing down.

Question 28

What is acceleration measured in?

Answer 28

Acceleration is measured in m/s².

Question 29

What is the slope on a velocity-time graph?

Answer 29

_Acceleration_ is the slope of a velocity-time graph?

Question 30

What is the equation that can be used when the acceleration ( a ) is not known or needed/ the first displacement equation?

Answer 30

∆d= v𝒊 + v𝐟 /2 t

Question 31

What is the equation that can be used when the final velocity ( v𝐟 ) is not known or needed/ the second displacement equation?

Answer 31

∆d= v𝒊 t + 1/2 a t ²

Question 32

What is the equation that can be used when the time ( t ) is not known or needed/ the quadratic formula?

Answer 32

0= at² + bt + c and t= -b ± √b² - 4ac/ 2a

Question 33

What is the equation that can be used when the time ( t ) is not known or needed/ the third displacement equation?

Answer 33

∆d= v𝐟 ² - v𝒊 ²/ 2a

Question 34

How to represent the acceleration due to gravity?

Answer 34

The symbol (g).

Question 35

What is the value for g?

Answer 35

g= 9.8 m/s²

Question 36

What does the sign you give g (+ or -) depend on?

Answer 36

The sign you give g (+ or -) depends on _the direction **YOU** choose as position,_ this is for up or down. **it does not matter what you choose up or down as positive but you must be consistent.

Question 37

The instantaneous vertical speed of any object at the top of its path is ……

Answer 37

zero.

Question 38

The _time_ it takes an object _to go up is …_

Answer 38

The same amount of time that it takes to come back down.

Question 39

What does displacement compare? aka how to calculate the displacement

Answer 39

Final position - initial position d= df-di

Question 40

When do you draw a tangent line?

Answer 40

When the question is asking you for an instantaneous speed or instantaneous velocity.