The weight of a truck is
shared by all tyres
The Sunday Nation
Nairobi,
15 August 2010
After reading last week’s article about tyre pressure, Josphat Maingi
remembered a puzzle that has been in his mind for a long time: “you know
the way the police check the weight of trucks by weighing the axels
separately, is it correct to assume that the total sum from all the
tyres is equal to the total load of the truck?”
Well; of course YES! Why would you expect it to be different? If the sum
from the different tyres were greater than the total weight, where would
the extra come from? Conversely, if it was smaller, where would the
shortage disappear to?
This is the reason why trucks have many tyres instead of the basic four
on a car. A fully laden 15-tonne lorry may weigh a total of 25T when we
add its own weight. With ten tyres (two in front and eight at the rear),
the load is shared at an average of about 2.5T per tyre.
However, depending of how the load is arranged, some of the tyres may
carry more weight than the rest. In addition, if the ground is not
level, the tyres on the lower end would also take extra weight.
The amount of weight shifted to the lower side depends on the angle of
tilting; the greater the tilt, the more weight transferred…all the time
keeping the total constant. For example, if the tilt is 5 degrees, about
9 per cent of the weight is shifted from the higher to the lower side.
At 10 degrees, the transfer is 17 per cent.
Luckily, however, the loading inspectors check the weight per axel and
not per tyre. The total of the two ends remains constant regardless of
the angle of tilting.
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Sam Kariuki has always wondered why FM stations are
on different wave bands around the country. For example, Nation Media
Group’s “Easy FM” transmits at
96.3MHz in
The reason is to avoid interference of signals from
different transmitting masts. The radio station may be located in
Now, even though the two signals are identical, the
one received at Nakuru will be delayed by a short duration. This is
mainly due to the electronic circuitry in the transmitters and the extra
distance traveled.
There would be problem for the listeners in Nakuru
and
The net result would be uncoordinated echoing and
whistling in the sound and that would make it impossible to listen. For
that reason, the two towns are allocated different frequencies so that
the in-between listeners can chose which the want to tune to. Obviously,
one radio set cannot be tuned to two frequencies simultaneously!
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