Mechanics

Front 1

Scalar quantities

Back 1

Quantities that only have size/magnitude, direction is irrelevant

Front 2

Vector quantities

Back 2

Has both size and direction

Front 3

Newton's first law of motion

Back 3

If the resultant force (unbalanced forces) of an object is zero, the acceleration of the object will be zero. An object with an acceleration of zero will either have a speed of zero (I.e; it'll be stationary) or it will have a constant velocity (constant speed in a straight line)

Front 4

Newton's second law of motion

Back 4

The relationship between the resultant force that acts on an object of mass, m, to produce the acceleration, a, of the object is: F =ma

The direction of the objects acceleration is the same as the direction of the resultant force on the object.

Front 5

Newton's third law of motion

Back 5

For every action force, there is an equal and opposite reaction force. The reaction force results from the action force. Often the reaction force is friction. The action force acts on one object and the reaction force acts on a different object.

Front 6

Newton's third law of motion

Back 6

For every action force, there is an equal and opposite reaction force. The reaction force results from the action force. Often the reaction force is friction. The action force acts on one object and the reaction force acts on a different object.

Front 7

Friction

Back 7

Friction is the force produced when two surfaces come in contact and 'grip' together without skipping past each other or when one surface slides over another. Friction forces act in many situations and always oppose the relative motion of the two surfaces involved.

Front 8

Newton's third law of motion

Back 8

For every action force, there is an equal and opposite reaction force. The reaction force results from the action force. Often the reaction force is friction. The action force acts on one object and the reaction force acts on a different object.

Front 9

Friction

Back 9

Friction is the force produced when two surfaces come in contact and 'grip' together without skipping past each other or when one surface slides over another. Friction forces act in many situations and always oppose the relative motion of the two surfaces involved.

Front 10

Air resistance

Back 10

Air resistance is friction caused when an object moves through air

Front 11

Newton's third law of motion

Back 11

For every action force, there is an equal and opposite reaction force. The reaction force results from the action force. Often the reaction force is friction. The action force acts on one object and the reaction force acts on a different object.

Front 12

Friction

Back 12

Friction is the force produced when two surfaces come in contact and 'grip' together without skipping past each other or when one surface slides over another. Friction forces act in many situations and always oppose the relative motion of the two surfaces involved.

Front 13

Air resistance

Back 13

Air resistance is friction caused when an object moves through air

Front 14

Torque

Back 14

Torque refers to the turning effect about a pivot. The size of a torque depends on the size of the force and the perpendicular distance from the pivot to the point where the force is applied.

Torque = Fd (unit = Newton metres)

Front 15

Newton's third law of motion

Back 15

For every action force, there is an equal and opposite reaction force. The reaction force results from the action force. Often the reaction force is friction. The action force acts on one object and the reaction force acts on a different object.

Front 16

Friction

Back 16

Friction is the force produced when two surfaces come in contact and 'grip' together without skipping past each other or when one surface slides over another. Friction forces act in many situations and always oppose the relative motion of the two surfaces involved.

Front 17

Air resistance

Back 17

Air resistance is friction caused when an object moves through air

Front 18

Torque

Back 18

Torque refers to the turning effect about a pivot. The size of a torque depends on the size of the force and the perpendicular distance from the pivot to the point where the force is applied.

Torque = Fd (unit = Newton metres)

Front 19

Couple

Back 19

A couple occurs where two equal and oppositely directed forces act at a distance apart. A couple causes rotation only.

Front 20

Equilibrium

Back 20

Equilibrium occurs when an object is at rest or moving uniformly. An object is described as being in equilibrium when both the resultant force is zero and the sum of all the torques acting on the force is zero. (Translational equilibrium and rotational equilibrium)

Front 21

Equilibrium

Back 21

Equilibrium occurs when an object is at rest or moving uniformly. An object is described as being in equilibrium when both the resultant force is zero and the sum of all the torques acting on the force is zero. (Translational equilibrium and rotational equilibrium)

Front 22

Weight of an object

Back 22

The weight of an object acts down through the object's centre of mass. This is the point at which if an object is suspended or pivoted, the object will balance.

Front 23

Equilibrium

Back 23

Equilibrium occurs when an object is at rest or moving uniformly. An object is described as being in equilibrium when both the resultant force is zero and the sum of all the torques acting on the force is zero. (Translational equilibrium and rotational equilibrium)

Front 24

Weight of an object

Back 24

The weight of an object acts down through the object's centre of mass. This is the point at which if an object is suspended or pivoted, the object will balance.

Front 25

Momentum

Back 25

Momentum is a quantity which involves the velocity and mass of an object. An object will have more momentum if it either has a lighter mass, is travelling at a faster velocity or has both. Momentum is calculated through the formula: p=mv

Front 26

Change in momentum

Back 26

When a force acts on an object and changes its motion, the objects momentum will also change. The change in momentum (delta p) is calculated from the formula: change in momentum = final momentum - initial momentum

Front 27

Conservation of momentum

Back 27

Momentum is conserved in collisions between objects and in explosions (I.e; total moments before equals total momentum after). This relationship only applies when no resultant external force is present such as gravity and friction. Momentum will be conserved in situations where these forces or where they have been balanced by reaction forces.

Front 28

Projectile motion

Back 28

The path travelled by a projectile is parabolic. This is because the only force that acts on a projectile is it's weight force, this means that as a projectile moves, it accelerates constantly downwards at 9.8m per second2. There is no accelerating force acting in the horizontal direction and so the projectile moves horizontally at a constant speed.

Front 29

Circular motion

Back 29

Motion around a circular (rotation), constant speed with only one force providing centripetal force)

Front 30

Circular motion

Back 30

Motion around a circular (rotation), constant speed with only one force providing centripetal force)

Front 31

Frequency of rotations

Back 31

Frequency of rotations is the number of rotations made per second (rpm or hertz)

Front 32

Acceleration for circular motion

Back 32

Centripetal force which is towards the inside of the circle causes the object to accelerate by changing the objects direction but not its speed. This acceleration is called the centripetal acceleration.