Answer:
the answer is The pneumatic mechanical device can only be used as a de-icing device.
Explanation:
An ice protection system prevents the formation of ice, or enables the aircraft to shed the ice before it can grow to a dangerous thickness. Ice protection systems are designed to keep atmospheric ice from accumulating on aircraft surfaces such as wings, propellers and engine intakes.
The pneumatic mechanical device is the Pneumatic deicing boots which was invented by the Goodrich Corporation in 1923. The pneumatic boot is usually made of layers of rubber, with one or more air chambers between the layers.
Any design which utilizes either a mechanical means of breaking the bond of ice to the surface, or which operates on a periodic cycle, is necessarily a de-ice system.
I changed my undershorts. The elastic on the old ones I put on that day was deteriorated, and it completely failed when I dripped lab coffee on it, causing falldown.
The gravitational force is inversely proportional to the
square of the distance between their centers. So the
force is greatest when the distance is zero.
Answer:
Speed of the speeder will be 28 m/sec
Explanation:
In first case police car is traveling with a speed of 90 km/hr
We can change 90 km/hr in m/sec
So 
Car is traveling for 1 sec with a constant speed so distance traveled in 1 sec = 25×1 = 25 m
After that car is accelerating with
for 7 sec
So distance traveled by car in these 7 sec

So total distance traveled by police car = 224 m
This distance is also same for speeder
Now let speeder is moving with constant velocity v
so 
v = 28 m/sec
Usually, it increases the solubility in water.