Page 57 - 05. Subyek Teknik Mesin - Automobile Mechanical and Electrical Systems Automotive Technology Vehicle Maintenance and Repair (Vehicle Maintenance Repr Nv2) by Tom Denton

1
42 Automobile mechanical and electrical systems

Hammer is lifted,
The weight of the giving it potential
hammer falling energy
has kinetic
energy

The blow of the hammer
converts the energy into
heat, sound and ‘spring’
energy as the pin is
compressed

Figure 1.56 Waiting for the hammer to fall

Distance

Force
Torque
Nut or wrench being
bolt head applied

The torque applied is the force in
newtons times the distance in metres

Figure 1.57 Torque wrench

electrical energy, e.g. that made by an alternator

●
chemical energy, e.g. stored in a battery
●
heat energy, e.g. from burning a fuel
●
nuclear energy – which is not yet used in motor vehicles, fortunately!
●
Power is the rate of doing work or converting energy. It is measured in watts. If
the work done, or energy converted, is E joules in t seconds, then the power P is
calculated by:
Power Work done/Time

P E t/

1.4.9 Force and torque
A force is thought of as any infl uence that tends to change the state of rest or the
motion in a straight line of an object, just like braking force slows a vehicle down.
If the body cannot move freely it will deform or bend. Force is a vector quantity,
which means it must have both size and direction; its unit is the newton (N).
Torque is the turning effect of force on an object ( Fig. 1.57 ). A car engine
produces a torque at the wheels. Torque is measured by multiplying the force by
its perpendicular distance away from the turning point; its unit therefore is the
newton metre (Nm).