2.2.1 Scalar and Vector Quantities

Question 1

Name all of the scalars.

Answer 1

SEPDDMV
Speed
Power
Energy
Distance
Density
Mass
Volume

Question 2

Name all of the vectors.

Answer 2

Why aM I VAPID:
Weight
Momentum
Velocity
Acceleration
Pressure 
Impulse
Displacement

Question 3

Define scalar

Answer 3

A quantity which has magnitude but not direction.

Question 4

Define vector

Answer 4

A quantity which has magnitude and direction.

Question 5

What is mass’s unit, definition and vector equivalent?

Answer 5

1. kg
2. The matter content of a body;
3. Weight

Question 6

What is density’s unit, definition and vector equivalent?

Answer 6

1. kgm^-3
2. Mass per unit volume;
3. Pressure

Question 7

What is volume’s unit, definition and vector equivalent?

Answer 7

1. m^3
2. Three-dimensional space occupied by a body;
   3, Impulse;

Question 8

What is distance’s unit, definition and vector equivalent?

Answer 8

1. m
2. Length from one point to another;
3. Displacement;

Question 9

What is speed’s unit, definition and vector equivalent?

Answer 9

1. ms^-1
2. Distance traveled per unit time;
3. Velocity;

Question 10

What is energy’s unit, definition and vector equivalent?

Answer 10

1. J
2. Work done;
3. Acceleration;

Question 11

What is power’s unit, definition and vector equivalent?

Answer 11

1. W or Js^-1
2. Energy converted or work done per unit time;
3. Momentum;

Question 12

What is weight’s unit, definition and scalar equivalent?

Answer 12

1. N
2. Force acting towards the centre of mass (downwards / centre of Earth);
3. Mass;
   Direction: towards the centre of mass (downwards / centre of Earth);

Question 13

What is pressure’s unit, definition and scalar equivalent?

Answer 13

1. Pa or Nm^-2
2. Force per unit area;
3. Density;
   Direction: towards the unit area;

Question 14

What is impulse’s unit, definition and scalar equivalent?

Answer 14

1. Kgms^-1
2. Force x time;
3. Volume;
   Direction: the direction of acceleration (as F=MA); towards the centre of mass of an object (Earth).

Question 15

What is displacement’s unit, definition and scalar equivalent?

Answer 15

1. m
2. Distance from a specific point in a particular direction;
3. Distance;
   Direction: the direction of the distance moved in.

Question 16

What is velocity’s unit, definition and scalar equivalent?

Answer 16

1. ms^-1
2. Displacement per unit time;
3. Speed;
   Direction: speed in a given direction;

Question 17

What is acceleration’s unit, definition and scalar equivalent?

Answer 17

1. ms^-2
2. Change in velocity per unit time;
3. Energy;
   Direction: the direction of velocity;

Question 18

What is momentum’s unit, definition and scalar equivalent?

Answer 18

1. kgms^-1
2. Mass x velocity;
3. Power;
   Direction: the direction of velocity;

Question 19

What is the equation, which connects average velocity, total displacement and time?

Answer 19

Average velocity = total displacement / time

Question 20

An athlete is running around a track, describe their total displacement and change in velocity, offering an explanation.

Answer 20

Both are zero, as:
1. Mathematically, the net displacement is zero, and so using

avj velocity = total displacement / time

avj velocity must be zero.
2. Velocity is negative in one direction and positive in the other, these directions cancel each other out, leaving only speed.