Analogue and Digital Signals
Analogue signals VARY. the analogue signal takes every value in its range.
Digital is either ON or OFF a digital signal will only take two values. (pulses)
A signal needs to be AMPLIFIED as both analogue and digital signals weaken as they travel.
They can also pick up interference and noise from other signals.
Digital signals are better quality because:
- Noise is less of a problem. Digital noise cannot get amplified and is easy to 'clean up'
- If you recieve an 'noisy' analogue signal, it will be difficult to determine what the orignial signal looked like.
- Therefore digital signals are HIGHER QUALITY.
Digital signals are also easy to process with computers.. because they are digital!
Digital technology can also transmit more information at a given time.
Momentum = mass x velocity
CHANGE OF MOMENTUM = RESULTANT FORCE X TIME FOR WHICH FORCE ACTS
(kg m/s) = (N) x (s)
in a collision you cannot really affect the change in momentum, the cars mass and change in velocity stay the SAME.
However, an average force can be LOWERED by slowing the object down over a longer time.
CRUMPLE ZONES: Crumple on impact, increasing the time taken for the car to stop.
Speed, Distance Time Graphs.
IMPORTANT STUFF for distance time graphs ;)
2. FLAT SECTIONS ARE WHERE IT HAS STOPPED.
3. THE STEEPER THE GRAPH, THE FASTER IT IS GOING.
THE HANS DEVICE
without HANS :)
In a motor vehicle accident, the head can move freely even while the body is restrained by a seatbelt or harness. This can create a pendulum motion that can cause stress on the neck and spine.
The resultant forces can cause whiplash in even low-speed crashes, but at high speed, the impact can cause basal skull fracture, a serious injury that can sometimes be fatal.
The Head And Neck Support System attaches the helmet to a "collar" that reaches over the driver's shoulders via two tethers. The aim is to limit the amount of motion as the tethers tighten and the collar remains stationary.