P10 Flashcards
Braking distance
The distance travelled by a vehicle during the time it takes for its brakes to act
Conservation of momentum
in a closed system, the total momentum before an event is equal to the total momentum after the event. Momentum is conserved in any collision or explosion, provided no external forces act on the objects that collide or explode
Directly proportional
a graph will show this if the line of best fit is a straight line through the origin
Elastic
a material is elastic if it is able to regain its shape after it has been squashed or stretched
Extension
the increase in length of a spring (or a strip of material) from its original length
Gravitational field strength
the force of gravity on an object of mass 1 kg (in newtons per kilogram, N/kg). It is also the acceleration of free fall
Inertia
the tendency of an object to stay at rest or to continue in uniform motion
Limit of proportionality
the limit for Hooke’s law applied to the extension of a stretched spring
Mass
the quantity of matter in an object – a measure of the difficulty of changing the motion of an object (in kilograms, kg)
Momentum
this equals mass (in kg) x velocity (in m/s)
Newton’s second law of motion
the acceleration of an object is proportional to the resultant force on the object, and inversely proportional to the mass of the object
Stopping distance
the distance travelled by the vehicle in the time it takes for the driver to think and brake
Terminal velocity
the velocity reached by an object when the drag force on it is equal and opposite to the force making it move
Thinking distance
the distance travelled by the vehicle in the time it takes the driver to react
Weight
the force of gravity on an object (in newtons, N)
