1.
ADe zwaartekrachtversnelling is 10 N/kg. Het oppervlak van de vis dat door het water erboven wordt samengedrukt, is 6 cm².2Bepaal de waterkracht boven de vis die op de vis inwerkt.
Bekend:
Versnelling als gevolg van zwaartekracht (g) = 10 N/kg
Surface area of fish (A) = 6 cm2 = 6 x 10-4 m2
Dichtheid of water = 1 gram/cm3 = 1 (10-3 kg) / 10-6 m3 = 103 kg / m3 = 1000 kg / m3
Height of water = 100 cm – 15 cm = 85 cm = 85 x 10-2 meter
Gewild : Force of the water above fish that acts on fish
oplossing:
Vergelijking van druk:
P = V / EEN
F = P A
F = ρ g h A
F = (1000)(10)(85 x 10-2)(6 x 10-4 m2)
F = (104)(510 x 10-6)
F = 510 x 10-2
F = 5.1 Newton
2. The normal pressure of blood is 80 mm hg to 120 mm hg. This value is equal to…
A. 80 Pascal to 120 Pascal
B. 800 Pascal to 1200 Pascal
C. 10256 Pascal to 17589 Pascal
D. 10526 Pascal to 15789 Pascal
Bekend:
The normal pressure of blood = 80 mm Hg – 120 mm Hg
Gezocht: This value is equal to… Pascal
oplossing:
The height of mercury in a barometer (above the surface of the sea) = 760 mm Hg
Pressure of air (above the surface of sea) = 1 atm = 1.0 x 105 Pascal
1 mm Hg = ……. Pascal?
80 mm Hg = 80 x 131.58 Pascal = 10,526 Pascal
120 mm Hg = 120 x 131.58 Pascal = 15,789 Pascal
Het juiste antwoord is D.
3. Above the surface of the sea, the height of mercury in a barometer is 760 mm. If at a place, the height of mercury in a barometer is 700 mm. Determine the pressure of air at that place.
Bekend:
The height of mercury in a barometer (above the surface of the sea) = 760 mm Hg
Pressure of air (above the surface of sea) = 1 atm = 1,013 x 105 Pascal
Gezocht: Determine the pressure of air if the height of mercury is 700 mm
oplossing:
760 mm Hg = 1.013 x 105 Pascal
700 mm Hg = ……… Pascal?
