Chapter 8 Modelling In Mechanics - Year 1

Question 1

Air Resistance

Answer 1

The friction which an object experiences through space (not astronomy space but any space)

Question 2

Lamina

Answer 2

A 2 D shape (length and width) which has mass which is evenly distributed across a flat surface

Question 3

Rod

Answer 3

An object with 1 dimension. It is rigid and therefore doesn’t bend of buckle.

There is no thickness

Question 4

Light

Answer 4

Mass which is regarded as 0

As a result tension is the same at both ends of a light object (for example a light string)

Question 5

Smooth

Answer 5

There is no friction between the smooth object and objects touching it.

Question 6

Wire

Answer 6

A rigid thin length if metal. It is treated as a 1 dimensional object. It can be smooth or rough.

Question 7

Rough

Answer 7

This means that something has friction

Question 8

Particle

Answer 8

The dimensions of an object are negligible as a result of this air resistance and rotational forces can be ignored.

It’s mass is concentrated around a single point

Question 9

Uniform body.

Answer 9

The mass is evenly distributed. The mass is concentrated at the geometric centre of the body (the centre of mass)

Question 10

Gravity

Answer 10

Is uniform at 9.8m/s2
It acts vertically downwards

Question 11

Inextensible

Answer 11

It don’t stretch.

If something is inextensible then acceleration is constant throughout the object.

Question 12

What is negative acceleration called?

Answer 12

Deceleration or Retardation

Question 13

What is the dimension of displacement?

Answer 13

Length

Question 14

What is the dimension of distance?

Answer 14

Length

Question 15

What is the dimension of velocity?

Answer 15

Length ÷ Time

Question 16

What is the dimension of speed?

Answer 16

Length ÷ Time

Question 17

What is the dimension of acceleration?

Answer 17

Velocity ÷ Time

Which is equal to

Length ÷ time^2

Question 18

What is the dimension of time?

Answer 18

None

Question 19

What is the dimension of mass?

Answer 19

None

Question 20

What is the dimension of weight and force?

Answer 20

Mass X Acceleration

Question 21

What is the SI unit for displacement?

Answer 21

Meters

Question 22

What is the SI unit for distance?

Answer 22

Meters

Question 23

What is the SI unit for speed?

Answer 23

ms^-1 or m/s

Question 24

What is the SI unit for acceleration?

Answer 24

ms^-2 or m/s^2

Question 25

What is the SI unit for time?

Answer 25

Seconds

Question 26

What is the SI unit for mass?

Answer 26

Kg

Question 27

What is the SI unit for weight and force?

Answer 27

Kgms^2 or Newtons

Question 28

cm to m?

Answer 28

÷100

Question 29

m to cm?

Answer 29

X 100

Question 30

mm to cm?

Answer 30

÷10

Question 31

cm - mm?

Answer 31

X10

Question 32

m to km?

Answer 32

÷ 1000

Question 33

km to m?

Answer 33

X1000

Question 34

Hours to minutes?

Answer 34

X60

Question 35

Minutes to hours?

Answer 35

÷60

Question 36

Minutes - seconds?

Answer 36

X60

Question 37

Seconds to minutes?

Answer 37

÷60

Question 38

Hours to seconds?

Answer 38

X3600

Question 39

Seconds to hours?

Answer 39

÷3600

Question 40

g/cm^3 - kg/m^3?

Answer 40

X1000

Question 41

Kg/m^3 - g/cm^3?

Answer 41

÷1000

Answer 42