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Bernoulli Equation

Fluid Mechanics · FE Reference Handbook section

Fluid Mechanics
8 formulas
10 exam-style examples
~60 min
All Fluid Mechanics lectures

Handbook notes for this section

Definitions and conditions exactly as the handbook states them.

  • The field equation is derived when the energy equation is applied to one-dimensional flows. Assuming no friction losses and
  • that no pump or turbine exists between sections 1 and 2 in the system,

Core formulas for this FE topic

Definitions, applicability, units, assumptions and worked examples for each relation.

Worked exam-style examples

The four ways this section is written on the real exam — thoughts first, then equations, then substitution.

Example 1
Hydrostatic pressure — solve for pressure — Bernoulli Equation

A fluid mechanics problem uses Hydrostatic pressure. Given unit weight (gamma) = 56.0000 lb/ft³; depth (h) = 12.5000 ft, determine the pressure (p) in psf.

Given

  • unitweight(gamma)=56.0000lb/ft3unit weight (gamma) = 56.0000 lb/ft^{3}
  • depth(h)=12.5000ftdepth (h) = 12.5000 ft

Find

pressure (p), in psf

Start with the thinking

  • The governing relation printed in this handbook section is Hydrostatic pressure.
  • Everything except p is given, so isolate p symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Fluid Mechanics items reward recognising the unknown before touching a calculator.

Step-by-step solution

  1. Step 1 — State the governing relation:

    p=γhp = \gamma h
  2. Step 2 — Rearrange the relation so that p stands alone on the left-hand side.

  3. Step 3

    Listthegivens:unitweight(gamma)=56.0000lb/ft3,depth(h)=12.5000ftList the givens: unit weight (gamma) = 56.0000 lb/ft^{3}, depth (h) = 12.5000 ft
  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    p=700.0 psfp = 700.0\ \text{psf}
  6. Step 6 — Check: returning p = 700.0 psf to

    p=γhp = \gamma h

    reproduces the given quantities, and both sides carry the same units.

Answer:
p=700.0 psfp = 700.0\ \text{psf}

Why the other options are there

  • 1,400 — kept a factor of two that cancels in the correct rearrangement.
  • 350.0 — dropped that same factor in the other direction.
  • 770.0 — rounded an intermediate value before the final step.

Reference: FE Reference Handbook — Fluid Mechanics → Bernoulli Equation

Example 2
Bernoulli equation — solve for pressure at 2 — Bernoulli Equation (2)

the Bernoulli equation across a pipe contraction Given pressure at 1 (p_1) = 164,800 Pa; velocity at 1 (V_1) = 2.5000 m/s; elevation at 1 (z_1) = 4.7000 m; velocity at 2 (V_2) = 1.7000 m/s; elevation at 2 (z_2) = 0.8000 m; specific weight (gamma) = 9,240 N/m^3, determine the pressure at 2 (p_2) in Pa.

Given

  • pressureat1(p1)=164,800Papressure at 1 (p_1) = 164,800 Pa
  • velocityat1(V1)=2.5000m/svelocity at 1 (V_1) = 2.5000 m/s
  • elevationat1(z1)=4.7000melevation at 1 (z_1) = 4.7000 m
  • velocityat2(V2)=1.7000m/svelocity at 2 (V_2) = 1.7000 m/s
  • elevationat2(z2)=0.8000melevation at 2 (z_2) = 0.8000 m
  • specificweight(gamma)=9,240N/m3specific weight (gamma) = 9,240 N/m^3

Find

pressure at 2 (p_2), in Pa

Start with the thinking

  • The governing relation printed in this handbook section is Bernoulli equation.
  • Everything except p_2 is given, so isolate p_2 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • The Bernoulli equation relates pressure, velocity, and elevation along a pipeline streamline.
D₁=200D₂=100V1V2

Figure 2 — schematic for Bernoulli equation — solve for pressure at 2 — Bernoulli Equation (2)

Step-by-step solution

  1. Step 1 — State the governing relation:

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2
  2. Step 2 — Rearrange the relation so that p_2 stands alone on the left-hand side.

  3. Step 3 — List the givens: pressure at 1 (p_1) = 164,800 Pa, velocity at 1 (V_1) = 2.5000 m/s, elevation at 1 (z_1) = 4.7000 m, velocity at 2 (V_2) = 1.7000 m/s, elevation at 2 (z_2) = 0.8000 m, specific weight (gamma) = 9,240 N/m^3.

  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    p2=202418 Pap_{2} = 202418\ \text{Pa}
  6. Step 6 — Check: returning p_2 = 202,418 Pa to

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2

    reproduces the given quantities, and both sides carry the same units.

Answer:
p2=202418 Pap_{2} = 202418\ \text{Pa}

Why the other options are there

  • 404,837 — kept a factor of two that cancels in the correct rearrangement.
  • 101,209 — dropped that same factor in the other direction.
  • 222,660 — rounded an intermediate value before the final step.

Reference: FE Handbook — Bernoulli Equation

Example 3
Hydrostatic pressure — solve for unit weight — Bernoulli Equation (3)

A fluid mechanics problem uses Hydrostatic pressure. Given depth (h) = 93.0000 ft; pressure (p) = 4,915 psf, determine the unit weight (gamma) in lb/ft³.

Given

  • depth(h)=93.0000ftdepth (h) = 93.0000 ft
  • pressure(p)=4,915psfpressure (p) = 4,915 psf

Find

unit weight (gamma), in lb/ft³

Start with the thinking

  • The governing relation printed in this handbook section is Hydrostatic pressure.
  • Everything except gamma is given, so isolate gamma symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Fluid Mechanics items reward recognising the unknown before touching a calculator.

Step-by-step solution

  1. Step 1 — State the governing relation:

    p=γhp = \gamma h
  2. Step 2 — Rearrange the relation so that gamma stands alone on the left-hand side.

  3. Step 3

    Listthegivens:depth(h)=93.0000ft,pressure(p)=4,915psfList the givens: depth (h) = 93.0000 ft, pressure (p) = 4,915 psf
  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    γ=52.8495 lb/ft³\gamma = 52.8495\ \text{lb/ft³}
  6. Step 6 — Check: returning gamma = 52.8495 lb/ft³ to

    p=γhp = \gamma h

    reproduces the given quantities, and both sides carry the same units.

Answer:
γ=52.8495 lb/ft³\gamma = 52.8495\ \text{lb/ft³}

Why the other options are there

  • 105.7 — kept a factor of two that cancels in the correct rearrangement.
  • 26.4247 — dropped that same factor in the other direction.
  • 58.1344 — rounded an intermediate value before the final step.

Reference: FE Reference Handbook — Fluid Mechanics → Bernoulli Equation

Example 4
Bernoulli equation — solve for velocity at 2 — Bernoulli Equation (4)

the Bernoulli equation for flow discharging from a tank nozzle Given pressure at 1 (p_1) = 336,900 Pa; velocity at 1 (V_1) = 0.8000 m/s; elevation at 1 (z_1) = 4.8000 m; pressure at 2 (p_2) = 203,500 Pa; elevation at 2 (z_2) = 3.2000 m; specific weight (gamma) = 9,320 N/m^3, determine the velocity at 2 (V_2) in m/s.

Given

  • pressureat1(p1)=336,900Papressure at 1 (p_1) = 336,900 Pa
  • velocityat1(V1)=0.8000m/svelocity at 1 (V_1) = 0.8000 m/s
  • elevationat1(z1)=4.8000melevation at 1 (z_1) = 4.8000 m
  • pressureat2(p2)=203,500Papressure at 2 (p_2) = 203,500 Pa
  • elevationat2(z2)=3.2000melevation at 2 (z_2) = 3.2000 m
  • specificweight(gamma)=9,320N/m3specific weight (gamma) = 9,320 N/m^3

Find

velocity at 2 (V_2), in m/s

Start with the thinking

  • The governing relation printed in this handbook section is Bernoulli equation.
  • Everything except V_2 is given, so isolate V_2 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • The Bernoulli equation relates pressure, velocity, and elevation along a pipeline streamline.
D₁=200D₂=100V1V2

Figure 4 — schematic for Bernoulli equation — solve for velocity at 2 — Bernoulli Equation (4)

Step-by-step solution

  1. Step 1 — State the governing relation:

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2
  2. Step 2 — Rearrange the relation so that V_2 stands alone on the left-hand side.

  3. Step 3 — List the givens: pressure at 1 (p_1) = 336,900 Pa, velocity at 1 (V_1) = 0.8000 m/s, elevation at 1 (z_1) = 4.8000 m, pressure at 2 (p_2) = 203,500 Pa, elevation at 2 (z_2) = 3.2000 m, specific weight (gamma) = 9,320 N/m^3.

  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    V2=17.6878 m/sV_{2} = 17.6878\ \text{m/s}
  6. Step 6 — Check: returning V_2 = 17.6878 m/s to

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2

    reproduces the given quantities, and both sides carry the same units.

Answer:
V2=17.6878 m/sV_{2} = 17.6878\ \text{m/s}

Why the other options are there

  • 35.3756 — kept a factor of two that cancels in the correct rearrangement.
  • 8.8439 — dropped that same factor in the other direction.
  • 19.4566 — rounded an intermediate value before the final step.

Reference: FE Handbook — Bernoulli Equation

Example 5
Hydrostatic pressure — solve for depth — Bernoulli Equation (5)

A fluid mechanics problem uses Hydrostatic pressure. Given unit weight (gamma) = 56.0000 lb/ft³; pressure (p) = 5,282 psf, determine the depth (h) in ft.

Given

  • unitweight(gamma)=56.0000lb/ft3unit weight (gamma) = 56.0000 lb/ft^{3}
  • pressure(p)=5,282psfpressure (p) = 5,282 psf

Find

depth (h), in ft

Start with the thinking

  • The governing relation printed in this handbook section is Hydrostatic pressure.
  • Everything except h is given, so isolate h symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Fluid Mechanics items reward recognising the unknown before touching a calculator.

Step-by-step solution

  1. Step 1 — State the governing relation:

    p=γhp = \gamma h
  2. Step 2 — Rearrange the relation so that h stands alone on the left-hand side.

  3. Step 3

    Listthegivens:unitweight(gamma)=56.0000lb/ft3,pressure(p)=5,282psfList the givens: unit weight (gamma) = 56.0000 lb/ft^{3}, pressure (p) = 5,282 psf
  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    h=94.3214 fth = 94.3214\ \text{ft}
  6. Step 6 — Check: returning h = 94.3214 ft to

    p=γhp = \gamma h

    reproduces the given quantities, and both sides carry the same units.

Answer:
h=94.3214 fth = 94.3214\ \text{ft}

Why the other options are there

  • 188.6 — kept a factor of two that cancels in the correct rearrangement.
  • 47.1607 — dropped that same factor in the other direction.
  • 103.8 — rounded an intermediate value before the final step.

Reference: FE Reference Handbook — Fluid Mechanics → Bernoulli Equation

Example 6
Bernoulli equation — solve for elevation at 2 — Bernoulli Equation (6)

the Bernoulli equation applied to a venturi meter Given pressure at 1 (p_1) = 148,600 Pa; velocity at 1 (V_1) = 2.8000 m/s; elevation at 1 (z_1) = 1.0000 m; pressure at 2 (p_2) = 319,000 Pa; velocity at 2 (V_2) = 3.5000 m/s; specific weight (gamma) = 9,140 N/m^3, determine the elevation at 2 (z_2) in m.

Given

  • pressureat1(p1)=148,600Papressure at 1 (p_1) = 148,600 Pa
  • velocityat1(V1)=2.8000m/svelocity at 1 (V_1) = 2.8000 m/s
  • elevationat1(z1)=1.0000melevation at 1 (z_1) = 1.0000 m
  • pressureat2(p2)=319,000Papressure at 2 (p_2) = 319,000 Pa
  • velocityat2(V2)=3.5000m/svelocity at 2 (V_2) = 3.5000 m/s
  • specificweight(gamma)=9,140N/m3specific weight (gamma) = 9,140 N/m^3

Find

elevation at 2 (z_2), in m

Start with the thinking

  • The governing relation printed in this handbook section is Bernoulli equation.
  • Everything except z_2 is given, so isolate z_2 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • The Bernoulli equation relates pressure, velocity, and elevation along a pipeline streamline.
D₁=200D₂=100V1V2

Figure 6 — schematic for Bernoulli equation — solve for elevation at 2 — Bernoulli Equation (6)

Step-by-step solution

  1. Step 1 — State the governing relation:

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2
  2. Step 2 — Rearrange the relation so that z_2 stands alone on the left-hand side.

  3. Step 3 — List the givens: pressure at 1 (p_1) = 148,600 Pa, velocity at 1 (V_1) = 2.8000 m/s, elevation at 1 (z_1) = 1.0000 m, pressure at 2 (p_2) = 319,000 Pa, velocity at 2 (V_2) = 3.5000 m/s, specific weight (gamma) = 9,140 N/m^3.

  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    z2=−17.8681 mz_{2} = -17.8681\ \text{m}
  6. Step 6 — Check: returning z_2 = -17.8681 m to

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2

    reproduces the given quantities, and both sides carry the same units.

Answer:
z2=−17.8681 mz_{2} = -17.8681\ \text{m}

Why the other options are there

  • -35.7362 — kept a factor of two that cancels in the correct rearrangement.
  • -8.9340 — dropped that same factor in the other direction.
  • -19.6549 — rounded an intermediate value before the final step.

Reference: FE Handbook — Bernoulli Equation

Example 7
Hydrostatic pressure — solve for pressure (case 2) — Bernoulli Equation (7)

A fluid mechanics problem uses Hydrostatic pressure. Given unit weight (gamma) = 59.0000 lb/ft³; depth (h) = 39.0000 ft, determine the pressure (p) in psf.

Given

  • unitweight(gamma)=59.0000lb/ft3unit weight (gamma) = 59.0000 lb/ft^{3}
  • depth(h)=39.0000ftdepth (h) = 39.0000 ft

Find

pressure (p), in psf

Start with the thinking

  • The governing relation printed in this handbook section is Hydrostatic pressure.
  • Everything except p is given, so isolate p symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Fluid Mechanics items reward recognising the unknown before touching a calculator.

Step-by-step solution

  1. Step 1 — State the governing relation:

    p=γhp = \gamma h
  2. Step 2 — Rearrange the relation so that p stands alone on the left-hand side.

  3. Step 3

    Listthegivens:unitweight(gamma)=59.0000lb/ft3,depth(h)=39.0000ftList the givens: unit weight (gamma) = 59.0000 lb/ft^{3}, depth (h) = 39.0000 ft
  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    p=2301 psfp = 2301\ \text{psf}
  6. Step 6 — Check: returning p = 2,301 psf to

    p=γhp = \gamma h

    reproduces the given quantities, and both sides carry the same units.

Answer:
p=2301 psfp = 2301\ \text{psf}

Why the other options are there

  • 4,602 — kept a factor of two that cancels in the correct rearrangement.
  • 1,151 — dropped that same factor in the other direction.
  • 2,531 — rounded an intermediate value before the final step.

Reference: FE Reference Handbook — Fluid Mechanics → Bernoulli Equation

Example 8
Bernoulli equation — solve for pressure at 2 (case 2) — Bernoulli Equation (8)

the Bernoulli equation across a pipe contraction Given pressure at 1 (p_1) = 236,100 Pa; velocity at 1 (V_1) = 1.4000 m/s; elevation at 1 (z_1) = 2.3000 m; velocity at 2 (V_2) = 5.3000 m/s; elevation at 2 (z_2) = 0.1000 m; specific weight (gamma) = 9,720 N/m^3, determine the pressure at 2 (p_2) in Pa.

Given

  • pressureat1(p1)=236,100Papressure at 1 (p_1) = 236,100 Pa
  • velocityat1(V1)=1.4000m/svelocity at 1 (V_1) = 1.4000 m/s
  • elevationat1(z1)=2.3000melevation at 1 (z_1) = 2.3000 m
  • velocityat2(V2)=5.3000m/svelocity at 2 (V_2) = 5.3000 m/s
  • elevationat2(z2)=0.1000melevation at 2 (z_2) = 0.1000 m
  • specificweight(gamma)=9,720N/m3specific weight (gamma) = 9,720 N/m^3

Find

pressure at 2 (p_2), in Pa

Start with the thinking

  • The governing relation printed in this handbook section is Bernoulli equation.
  • Everything except p_2 is given, so isolate p_2 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • The Bernoulli equation relates pressure, velocity, and elevation along a pipeline streamline.
D₁=200D₂=100V1V2

Figure 8 — schematic for Bernoulli equation — solve for pressure at 2 (case 2) — Bernoulli Equation (8)

Step-by-step solution

  1. Step 1 — State the governing relation:

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2
  2. Step 2 — Rearrange the relation so that p_2 stands alone on the left-hand side.

  3. Step 3 — List the givens: pressure at 1 (p_1) = 236,100 Pa, velocity at 1 (V_1) = 1.4000 m/s, elevation at 1 (z_1) = 2.3000 m, velocity at 2 (V_2) = 5.3000 m/s, elevation at 2 (z_2) = 0.1000 m, specific weight (gamma) = 9,720 N/m^3.

  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    p2=244539 Pap_{2} = 244539\ \text{Pa}
  6. Step 6 — Check: returning p_2 = 244,539 Pa to

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2

    reproduces the given quantities, and both sides carry the same units.

Answer:
p2=244539 Pap_{2} = 244539\ \text{Pa}

Why the other options are there

  • 489,078 — kept a factor of two that cancels in the correct rearrangement.
  • 122,269 — dropped that same factor in the other direction.
  • 268,993 — rounded an intermediate value before the final step.

Reference: FE Handbook — Bernoulli Equation

Example 9
Hydrostatic pressure — solve for unit weight (case 2) — Bernoulli Equation (9)

A fluid mechanics problem uses Hydrostatic pressure. Given depth (h) = 94.0000 ft; pressure (p) = 1,964 psf, determine the unit weight (gamma) in lb/ft³.

Given

  • depth(h)=94.0000ftdepth (h) = 94.0000 ft
  • pressure(p)=1,964psfpressure (p) = 1,964 psf

Find

unit weight (gamma), in lb/ft³

Start with the thinking

  • The governing relation printed in this handbook section is Hydrostatic pressure.
  • Everything except gamma is given, so isolate gamma symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • Fluid Mechanics items reward recognising the unknown before touching a calculator.

Step-by-step solution

  1. Step 1 — State the governing relation:

    p=γhp = \gamma h
  2. Step 2 — Rearrange the relation so that gamma stands alone on the left-hand side.

  3. Step 3

    Listthegivens:depth(h)=94.0000ft,pressure(p)=1,964psfList the givens: depth (h) = 94.0000 ft, pressure (p) = 1,964 psf
  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    γ=20.8936 lb/ft³\gamma = 20.8936\ \text{lb/ft³}
  6. Step 6 — Check: returning gamma = 20.8936 lb/ft³ to

    p=γhp = \gamma h

    reproduces the given quantities, and both sides carry the same units.

Answer:
γ=20.8936 lb/ft³\gamma = 20.8936\ \text{lb/ft³}

Why the other options are there

  • 41.7872 — kept a factor of two that cancels in the correct rearrangement.
  • 10.4468 — dropped that same factor in the other direction.
  • 22.9830 — rounded an intermediate value before the final step.

Reference: FE Reference Handbook — Fluid Mechanics → Bernoulli Equation

Example 10
Bernoulli equation — solve for velocity at 2 (case 2) — Bernoulli Equation (10)

the Bernoulli equation for flow discharging from a tank nozzle Given pressure at 1 (p_1) = 157,400 Pa; velocity at 1 (V_1) = 1.7000 m/s; elevation at 1 (z_1) = 0.3000 m; pressure at 2 (p_2) = 266,200 Pa; elevation at 2 (z_2) = 2.0000 m; specific weight (gamma) = 9,630 N/m^3, determine the velocity at 2 (V_2) in m/s.

Given

  • pressureat1(p1)=157,400Papressure at 1 (p_1) = 157,400 Pa
  • velocityat1(V1)=1.7000m/svelocity at 1 (V_1) = 1.7000 m/s
  • elevationat1(z1)=0.3000melevation at 1 (z_1) = 0.3000 m
  • pressureat2(p2)=266,200Papressure at 2 (p_2) = 266,200 Pa
  • elevationat2(z2)=2.0000melevation at 2 (z_2) = 2.0000 m
  • specificweight(gamma)=9,630N/m3specific weight (gamma) = 9,630 N/m^3

Find

velocity at 2 (V_2), in m/s

Start with the thinking

  • The governing relation printed in this handbook section is Bernoulli equation.
  • Everything except V_2 is given, so isolate V_2 symbolically first — never rearrange after the numbers are in.
  • Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
  • The Bernoulli equation relates pressure, velocity, and elevation along a pipeline streamline.
D₁=200D₂=100V1V2

Figure 10 — schematic for Bernoulli equation — solve for velocity at 2 (case 2) — Bernoulli Equation (10)

Step-by-step solution

  1. Step 1 — State the governing relation:

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2
  2. Step 2 — Rearrange the relation so that V_2 stands alone on the left-hand side.

  3. Step 3 — List the givens: pressure at 1 (p_1) = 157,400 Pa, velocity at 1 (V_1) = 1.7000 m/s, elevation at 1 (z_1) = 0.3000 m, pressure at 2 (p_2) = 266,200 Pa, elevation at 2 (z_2) = 2.0000 m, specific weight (gamma) = 9,630 N/m^3.

  4. Step 4 — Substitute the given values into the rearranged relation.

  5. Step 5 — Evaluate:

    V2=0.1000 m/sV_{2} = 0.1000\ \text{m/s}
  6. Step 6 — Check: returning V_2 = 0.1000 m/s to

    p1γ+V122g+z1=p2γ+V222g+z2\dfrac{p_1}{\gamma} + \dfrac{V_1^2}{2g} + z_1 = \dfrac{p_2}{\gamma} + \dfrac{V_2^2}{2g} + z_2

    reproduces the given quantities, and both sides carry the same units.

Answer:
V2=0.1000 m/sV_{2} = 0.1000\ \text{m/s}

Why the other options are there

  • 0.2000 — kept a factor of two that cancels in the correct rearrangement.
  • 0.0500 — dropped that same factor in the other direction.
  • 0.1100 — rounded an intermediate value before the final step.

Reference: FE Handbook — Bernoulli Equation

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