Movement and Position

Question 1

What do different lines mean on a distance time graph?

Straight line going up, steep vs shallow straight line, horizontal line, curve, curve increasing vs decreasing

Answer 1

• Straight line represents a constant speed
• A steep straight line means a fast constant speed, a shallow straight line means a slow constant speed
• A horizontal line means the object is stationary
• A curve represents a changing speed
• An increasing curve means an increasing speed, a decreasing curve means a decreasing speed

The distance cannot go down, so unless stationary, the lines are always going upwards

Question 2

What is the relationship between distance moved, average speed and time taken? (Speed, distance and time)

Answer 2

• Speed = Distance/Time
• S = D/T

Question 3

How would you work out the average speed from a distance time graph?

Answer 3

• Speed = Gradient
• Speed = Rise/Run
• Speed = Distance/Time

Question 4

What is the difference between distance and displacement?

Answer 4

• Distance is the distance travelled by an object in total, even if they end up in the same spot, while displacement is the distance travelled by an object in a particular direction
• Distance is a scalar quantity, displacement is a vector quantity

Question 5

What is the difference between speed and velocity?

Answer 5

• Velocity is the displacement of an object over time, speed is the distance travelled by an object over time
• Speed is a scalar quantity, velocity is a vector quantity

Question 6

What is acceleration?

Answer 6

The rate of change of velocity

Question 7

What is the relationship between acceleration, change in velocity and time taken?

Answer 7

• Acceleration = Change in velocity/Time
• A = V-U/T

• Change in velocity is found by subtracting final velocity (V) from initial velocity (U)
• If the final value is negative, than the object is decelerating

Question 8

What do different lines mean on a velocity time graph?

Straight line going up vs going down, steep vs shallow straight line, horizontal line, curve

Answer 8

• Straight lines represent a constant acceleration, a straight line going down represents a constant deceleration
• A steep straight line represents a large constant acceleration/deceleration, a shallow straight line represents a small constant acceleration/deceleration
• A horizontal line represents a constant speed
• A curve represents an increasing/decreasing acceleration

Question 9

How would you work out the acceleration from a velocity time graph?

Answer 9

• Acceleration = Gradient
• Acceleration = Rise/Run
• Acceleration = Final Velocity-Initial Velocity/Time

Question 10

How do you work out distance travelled from a velocity time graph?

Answer 10

• Work out the total area under the graph
• To do this, seperate the graph into shapes of triangles and squares, and use the formulae (1/2 x Base x Height) for triangles and (Base x Height) for rectangles

Question 11

What is the relationship between final speed, initial speed, acceleration and distance travelled?

Answer 11

• (Final Speed)² = (Initial Speed)² + (2 x acceleration x distance travelled)
• V² = U² + (2 x A x S)
• A = (V²-U²/2S) (rearranged)

This is for when time is not given