Do not go on to the next question until you have correctly answered the question you are on.
What is pressure?
It is the force exerted by liquids against the walls of a container.
A number that expresses how the force is shared out on a surface.
It is equal to the force times the surface under the influence of the force.
When you multiply a pressure in Pa by a surface in m2, you get Pa•m2.
What magnitude is measured in these units?
Density.
Force.
Mass.
Is pressure a force?
Yes, because if there were no force, there would be no pressure.
Yes, because when the force increases, the pressure increases, and when the forces diminishes, so does the pressure.
No, the pressure depends on the surface and the force exerted on it.
2 atm is the pressure...
on the walls of an underwater object at a depth of 2m.
that you would usually find inside the wheels of a car.
the pressure at the top of Mount Everest.
A high pressure cleaner creates a 120 bar jet of water, which is approximately...
120 Pa
120 atm
1.2 atm
Imagine two 120 bar high pressure cleaners. One ejects 300 litres per hour and the other ejects 360 litres per hour. Which creates a stronger jet?
Both jets are at the same pressure. Therefore, both have equal strength.
The one with the thinnest jet will produce a stronger jet.
The one with a greater volume flow rate. The jet will have a greater cross section. As the force is equal to the pressure times the cross section, the thickest jet will have a greater strength.
Is the force caused by hydrostatic pressure perpendicular to the surface of an immersed object?
No, it is perpendicular to the walls of containers. When you rotate an immersed object it is possible to orient it so that the pressure is smaller.
Yes. Otherwise, if we immersed a tube horizontally, it would be possible to orient it in such a way that the pressure at the ends was different. This would cause a flow of water from one end to the other, but this flow does not take place.
It depends on the depth at which the object is immersed.
Is the following statement true in every case? "If a force of 1000 N is exerted on a 0.01 m2 surface, the pressure is equal to 100000 Pa"
Yes, because 100 000 Pa times 0,01 m2 is equal to the force 1000 N.
No, this value of the pressure is only correct if the force is exerted along the direction perpendicular to the surface.
Yes, because if you divide the force by the surface, you get 100000 Pa.
Is the following statement correct? "The hydrostatic pressure at a point is greater when the amount of fluid directly above the point is greater."
No. The hydrostatic pressure at any point of a liquid depends only on the height of the liquid above the point.
Yes, because the weight of the fluid above the point makes the pressure greater.
Yes, because a large weight is a consequence of a large mass, and a large mass corresponds to a large density. The hydrostatic pressure is proportional to the density.
One of the branches of a U-shaped tube has water in it and the other is full of mercury. In which of the branches will the height of the liquid be greater?
Both branches will reach the same height.
The branch with water in it.
The branch with mercury in it.
In a hydraulic press, which piston carries out more work?
Both pistons carry out the same amount of work.
The piston with a smaller cross section.
The piston with a larger cross section.
The radius of one of the pistons in a hydraulic press is double the radius of the other piston. What is the relation between the force on the large piston and the force on the small piston?
The force on the large piston is double the force on the small piston.
The force on the large piston is a quarter of the force on the small piston.
The force on the large piston is quadruple the force on the small piston.
What is the real value of the pressure of a gas connected to a manometer which has its other branch open to the atmosphere?
The pressure read on the manomenter.
The value read on the manometer minus the value of the atmospheric pressure.
The value read on the manometer plus the value of the atmospheric pressure.
How can you use hydrostatics to turn a force exerted in a definite direction into a force with double magnitude exerted in the opposite direction?
Creating a jet of water that leaves a compressor activated with the initial force.
Necessarily, using a hydraulic press in which one piston has a surface area which is double that of the other piston.
Using a hydraulic press full of mercury with a piston with a surface area double that of the other piston.
Kitchen sinks have a "bowl syphon" What is it for?
To increase the emptying rate.
To prevent bad smells.
To get a constant emptying rate.
If someone has a systolic arterial blood pressure of 12 and a diastolic blood pressure of 8, what are the values of the pressure in mmHg?
