Density – Mass / Volume
Density of water = 1000 kg/m3
Speed – the distance travelled by an object per unit time
Speed - Distance / Time
Distance = area under speed time graph
Area of | rectangle : WxH | triangle : ½ bh
Speed = gradient of distance time graph
Acceleration – the rate of change of an object’s velocity
Acceleration = v-u/t
Acceleration = gradient of speed time graph
i. They can be represented by arrows
ii. A force can make an object change speed
iii. A force can change the direction in which the object is moving
The resultant force is the single force that has the same effect as two or more forces
The acceleration caused by the pull of earth’s gravity is called acceleration of free fall ( 10 m/s2 )
Weight = mass x acceleration of free fall / W = mg
The mass of an object is measured in kilograms, tells you how much matter it is composed of.
The weight of an object is measured in Newtons, is the gravitational force that acts on it.
When parachutist stops accelerating, they fall at a steady rate called terminal velocity
The greater the mass of an object, the smaller the acceleration it is given by a particular force.
Force – the action of on body on a second body which causes its velocity to change.
Force = mass x acceleration , F = ma
Impulse – Ft = mv-mu
Momentum – the quantity of mass x velocity
Impulse equation ; impulse of force = change of momentum
The principle of the conservation of momentum - total momentum before = total momentum after
Vector quantities – have both magnitude and direction ( ie; velocity, force, weight )
Scalar quantities – only has magnitude ( ie; speed, mass, energy, density )
Moment – the quantity that tells us the turning effect of a force about a pivot
The moment of a force is bigger if :
i. The force is bigger
ii. It acts further from the pivot
iii. It acts at 90° the object it acts on
Moment of a force – the turning effect of a force about a point ( force x perpendicular...