Linear motion

Question 1

What is linear motion?

Answer 1

Linear motion is the movement in a straight or curved line.

Question 2

What is direct force?

Answer 2

Direct force is a force applied through the centre of mass resulting in linear motion.

Question 3

What is linear motion created by?

Answer 3

Linear motion is created by direct force.

Question 4

What are the linear motion quantities?

Answer 4

The linear motion quantities are distance, displacement, speed, velocity, acceleration/deceleration.

Question 5

What is distance and it’s unit of measurement?

Answer 5

Distance is the length of the path taken by a body moving from one position to another. Measured in metres, (m).

Question 6

What is displacement and it’s unit of measurement.

Answer 6

Displacement is the shortest straight-line route between two positions. Measured in metres, (m).

Question 7

What is speed, how is it calculated and what is it’s unit of measurement?

Answer 7

Speed is the movement of a body per unit of time (without reference to direction). Calculated by distance/time. Measured in metres per second, (m/s).

Question 8

What is velocity, how is it calculated and what is it’s unit of measurement?

Answer 8

Velocity is the speed of something in a given direction. Calculated by displacement/time OR distance/time. Measured in metres per second, (m/s).

Question 9

What is acceleration/deceleration, how is it calculated and what is it’s unit of measurement?

Answer 9

Acceleration is the rate of change of velocity. Calculated by (change in velocity)/time. Meters per second per second, (m/s2).

Question 10

What is a distance/time graph?

Answer 10

1. A distance/time graph shows the distance a body travels over a period of time
2. The gradient of the curve indicates the speed of a body at a particular instant
3. There are 4 types of line
   a) Rest, line is straight and horizontal
   b) Acceleration, line curves outwards from low to high
   c) Constant speed, line is in a straight line diagonally
   d) Deceleration, line curves inwards to plateau.

Question 11

What is a speed/time graph?

Answer 11

1. A speed/time graph shows the speed of a body over a particular time
2. The gradient of the curve indicates the acceleration/deceleration of the body at a particular time
3. There are 3 types of line
   a) Constant speed, line is straight and horizontal
   b) Acceleration, line curves outwards from low to high
   c) Deceleration, line curves outwards from the top to the bottom of the graph.

Question 12

What is a velocity/time graph?

Answer 12

1. A velocity/time graph shows the velocity of a body over a period of time
2. The gradient of the curve indicates the acceleration or deceleration of a body
3. E.g. a ski jumper descending down the ramp would see a line increase inwards, then plateau in a straight and horizontal line
4. E.g. a ball being passed between 2 players would see a straight line upwards turning back downwards. Then a line moving downwards, then moving back upwards.