1 Forces and motion
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Forces and motion units
1.1Core mechanics units
Use the units kilogram (kg), metre (m), metre per second (m/s), metre per second squared (m/s²), newton (N), second (s) and newton per kilogram (N/kg).
1.2PAdditional mechanics units
Use the following units: newton metre (Nm), kilogram metre/second (kg m/s)
(b) Movement and position
1.3Distance-time graphs
Plot and explain distance-time graphs
1.4Average speed equation
Know and use average speed = distance moved ÷ time taken.
1.5Motion practical
Practical: investigate the motion of everyday objects such as toy cars or tennis balls
1.6Acceleration equation
Know and use acceleration = change in velocity ÷ time taken, a = (v − u) ÷ t.
1.7Velocity-time graphs
Plot and explain velocity-time graphs
1.8Acceleration from graph gradients
Determine acceleration from the gradient of a velocity-time graph
1.9Distance from velocity-time graphs
Determine the distance travelled from the area between a velocity-time graph and the time axis
1.10Final speed equation
Use (final speed)² = (initial speed)² + 2 × acceleration × distance moved, v² = u² + 2as.
(c) Forces, movement, shape and momentum
1.11Effects of forces
Describe the effects of forces between bodies such as changes in speed, shape or direction
1.12Types of force
Identify different types of force such as gravitational or electrostatic
1.13Vectors and scalars
Understand how vector quantities differ from scalar quantities
1.14Force as a vector
Understand that force is a vector quantity
1.15Resultant force
Calculate the resultant force of forces that act along a line
1.16Friction
Know that friction is a force that opposes motion
1.17Force, mass and acceleration
Know and use unbalanced force = mass × acceleration, F = ma.
1.18Weight equation
Know and use weight = mass × gravitational field strength, W = mg.
1.19Stopping distance
Know that the stopping distance of a vehicle is made up of the sum of the thinking distance and the braking distance
1.20Factors affecting stopping distance
Describe the factors affecting vehicle stopping distance, including speed, mass, road condition and reaction time
1.21Falling objects and terminal velocity
Describe the forces acting on falling objects (and explain why falling objects reach a terminal velocity)
1.22Force-extension practical
Practical: investigate how extension varies with applied force for helical springs, metal wires and rubber bands
1.23Hooke’s law region
Know that the initial linear region of a force-extension graph is associated with Hooke’s law
1.24Elastic behaviour
Describe elastic behaviour as the ability of a material to recover its original shape after the forces causing deformation have been removed
1.25PMomentum equation
Know and use momentum = mass × velocity, p = mv.
1.26PMomentum and safety features
Use the idea of momentum to explain safety features
1.27PConservation of momentum
Use the conservation of momentum to calculate the mass, velocity or momentum of objects
1.28PForce and momentum change
Use force = change in momentum ÷ time taken, F = Δp/t = (mv − mu)/t.
1.29PNewton’s third law
Demonstrate an understanding of Newton’s third law
1.30PMoments equation
Know and use moment = force × perpendicular distance from the pivot.
1.31PCentre of gravity
Know that the weight of a body acts through its centre of gravity
1.32PPrinciple of moments
Use the principle of moments for a simple system of parallel forces acting in one plane
1.33PForces on a supported beam
Understand how the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam