4.5.6.1.5

4.5.6.1.5 Acceleration

4.5.6.1.5 Acceleration

Content

The average acceleration of an object can be calculated using the equation:

acceleration, a, in metres per second squared, m/s2

change in velocity, ∆v, in metres per second, m/s

time, t, in seconds, s

An object that slows down is decelerating.

Students should be able to estimate the magnitude of everyday accelerations.

The acceleration of an object can be calculated from the gradient of a velocity–time graph.

(HT only) The distance travelled by an object (or displacement of an object) can be calculated from the area under a velocity–time graph.

Students should be able to:

  • draw velocity–time graphs from measurements and interpret lines and slopes to determine acceleration
  • (HT only) interpret enclosed areas in velocity–time graphs to determine distance travelled (or displacement)
  • (HT only) measure, when appropriate, the area under a velocity–time graph by counting squares.

he following equation applies to uniform acceleration:

MS 3b, 3c

Students should be able to apply this equation which is given on the Physics equation sheet.

22

v u = 2 a s

2 2

final velocity − initial velocity = 2 × acceleration × distance

final velocity, v, in metres per second, m/s

initial velocity, u, in metres per second, m/s

acceleration, a, in metres per second squared, m/s2

distance, s, in metres, m

Near the Earth’s surface any object falling freely under gravity has an acceleration of about 9.8 m/s2.

An object falling through a fluid initially accelerates due to the force of gravity. Eventually the resultant force will be zero and the object will move at its terminal velocity.

(Physics only) Students should be able to:

• •

draw and interpret velocity–time graphs for objects that reach terminal velocity

interpret the changing motion in terms of the forces acting.

WS 3.3 - Carrying out and represent mathematical and statistical analysis.


WS 3.5 Interpreting observations and other data (presented in verbal, diagrammatic, graphical, symbolic or numerical form), including identifying patterns and trends, making inferences and drawing conclusions.


AT 1 :Use of appropriate apparatus to make and record a range of measurements accurately, including length, area, mass, time, volume and temperature. Use of such measurements to determine densities of solid and liquid objects (links to A-level AT a and b).


AT 2 :Use of appropriate apparatus to measure and observe the effects of forces including the extension of springs (links to A-level AT a).


MS 1d Make estimates of the results of simple calculations

MS 3b Change the subject of an equation

MS 3c Substitute numerical values into algebraic equations using appropriate units for physical quantities

MS 4a Translate information between graphical and numeric form

MS 4b Understand that y = mx + c represents a linear relationship

MS 4c Plot two variables from experimental or other data

MS 4d Determine the slope and intercept of a linear graph

MS 4f Understand the physical significance of area between a curve and the x-axis and measure it by counting squares as appropriate

Resources

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Practicals

Practical

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