Pressure caused by beam of molecular oxygen

In summary, the problem involves calculating the pressure exerted by a beam of molecular oxygen with a specific density and velocity striking a plate at a 30 degree angle. The equation provided in the conversation is not applicable, as it is for gas inside a container. Instead, the number of particles per second per unit area that cross the plane normal to the beam must be computed, taking into account the decrease in number due to the angle. The momentum change of each particle must then be calculated, and this will in turn give the rate of change of momentum per unit area, which is equal to pressure. A vector diagram may be helpful in visualizing this problem.
  • #1
TheGreatExplainer

Homework Statement


A beam of molecular oxygen containing 1010 molecules/cm3 and average speed of 500 m/s strikes (elastic collision) a plate at an angle of 30º with the normal direction.
Calculate the exerted pressure on the plate.

Homework Equations


P = Impluse x Flux

The Attempt at a Solution


I tried to use the equation in the attached file but in this case we have a constant angle so I can´t just simply integrate.

Any help would be appreciated.
 

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  • #2
TheGreatExplainer said:

Homework Statement


A beam of molecular oxygen containing 1010 molecules/cm3 and average speed of 500 m/s strikes (elastic collision) a plate at an angle of 30º with the normal direction.
Calculate the exerted pressure on the plate.

Homework Equations


P = Impluse x Flux

The Attempt at a Solution


I tried to use the equation in the attached file but in this case we have a constant angle so I can´t just simply integrate.

Any help would be appreciated.
The equation you have in the "link" looks like it is for the pressure that a gas has when it is inside a container. It does not apply here. In some ways this problem is easier, because the beam is only going in one direction, and every particle has the same velocity. ## \\ ## First of all, you need to compute ## m ## for the molecule. ## \\ ## Next, the number of incident particles/unit time per unit area will be decreased from that of the normal direction because of the ## 30^o ## angle. The first thing you need though is the number of particles per second per unit area that cross the plane normal to the beam. Then find the number per second incident at the surface tilted at ## 30^o ##. You then need to compute the momentum change of each particle. Once you have that, it should start to come together. ## \\ ## An additional input: Since Force is equal to the rate of change of momentum, the Pressure, which is force/area, should equal to the rate of change of momentum per unit area=you need to find how much the momentum is changing per second per unit area. ## \\ ## Suggestion: Draw a vector diagram to compute the momentum change of each molecule.
 
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Related to Pressure caused by beam of molecular oxygen

1. What is the definition of pressure caused by a beam of molecular oxygen?

Pressure caused by a beam of molecular oxygen refers to the force exerted by the collision of oxygen molecules with a surface. This force is measured per unit area and is typically expressed in units of Pascals (Pa).

2. How is pressure caused by a beam of molecular oxygen calculated?

The pressure caused by a beam of molecular oxygen can be calculated by dividing the force of the collisions by the area of the surface. This can be expressed as P = F/A, where P is pressure, F is force, and A is area.

3. What factors can affect the pressure caused by a beam of molecular oxygen?

The pressure caused by a beam of molecular oxygen can be affected by factors such as the speed and density of the oxygen molecules, as well as the angle and surface area of the surface that the molecules are colliding with.

4. How does pressure caused by a beam of molecular oxygen impact objects?

The pressure caused by a beam of molecular oxygen can have various impacts on objects depending on the intensity and duration of the collisions. It can cause objects to deform, break, or move, and can also affect the temperature and chemical reactions of the object's surface.

5. What are some real-life applications of pressure caused by a beam of molecular oxygen?

Pressure caused by a beam of molecular oxygen has many practical applications, such as in gas pumps, aerosol spray cans, and scuba diving tanks. It is also used in industrial processes, such as welding and cutting, and in medical treatments, such as oxygen therapy and carbon dioxide laser surgery.

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