Which one? Sam Golbach or Colby Brock

How high a building could fire hoses effectively spray from the ground? Fire hose pressures are around 1 MPa. (It is also said t

Mrac [35]

Answer:

$z_{2} = 91.640\,m$

Explanation:

The phenomenon can be modelled after the Bernoulli's Principle, in which the sum of heads related to pressure and kinetic energy on ground level is equal to the head related to gravity.

$\frac{P_{1}}{\rho\cdot g} + \frac{v_{1}^{2}}{2\cdot g}= z_{2}+\frac{P_{2}}{\rho\cdot g}$

The velocity of water delivered by the fire hose is:

$v_{1} = \frac{(300\,\frac{gal}{min} )\cdot(\frac{3.785\times 10^{-3}\,m^{3}}{1\,gal} )\cdot(\frac{1\,min}{60\,s} )}{\frac{\pi}{4}\cdot (0.3\,m)^{2}}$

$v_{1} = 0.267\,\frac{m}{s}$

The maximum height is cleared in the Bernoulli's equation:

$z_{2}= \frac{P_{1}-P_{2}}{\rho\cdot g} + \frac{v_{1}^{2}}{2\cdot g}$

$z_{2}= \frac{1\times 10^{6}\,Pa-101.325\times 10^{3}\,Pa}{(1000\,\frac{kg}{m^{3}} )\cdot(9.807\,\frac{m}{s^{2}} )} + \frac{(0.267\,\frac{m}{s} )^{2}}{2\cdot (9.807\,\frac{m}{s^{2}} )}$

$z_{2} = 91.640\,m$

7 0

3 years ago

Problem 7.16 (GO Tutorial) A cylindrical bar of steel 10.4 mm (0.4094 in.) in diameter is to be deformed elastically by applicat

shepuryov [24]

Answer:

P = 18035.25 N

Explanation:

Given

D = 10.4 mm

ΔD = 3.2 ×10⁻³ mm

E = 207 GPa

ν = 0.30

If

σ = P/A

A = 0.25*π*D²

σ = E*εx

ν = - εz / εx

εz = ΔD / D

We can get εx as follows

εz = ΔD / D = 3.2 ×10⁻³ mm / 10.4 mm = 3.0769*10⁻⁴

Now we find εx

ν = - εz / εx ⇒ εx = - εz / ν = - 3.0769*10⁻⁴ / 0.30 = - 1.0256*10⁻³

then

σ = E*εz = (207 GPa)*(-1.0256*10⁻³) = - 2.123*10⁸ Pa

we have to obtain A:

A = 0.25*π*D² = 0.25*π*(10.4*10⁻3)² = 8.49*10⁻⁵ m²

Finally we apply the following equation in order o get P

σ = P/A ⇒ P = σ*A = (- 2.123*10⁸Pa)*(8.49*10⁻⁵ m²) = 18035.25 N

4 0

3 years ago

ladders are not required to be inspected for visible defects prior to the first use of each work shift,and after any occuurrence

zaharov [31]

Answer:

The answer is False.

Explanation:

When it comes to occupational safety,<em> it is very important for ladders to be inspected by a qualified person before each use.</em> This is because ladders undergo conditions that impact their integrity while being in use. The inspection is also essential in order for the ladder to be timely replaced.

<u><em>Ladder accidents or ladder-related injuries happen every year.</em></u> Around 700 occupational deaths due to elevated fall from a ladder accounts for 15% of all occupational deaths. Misuse or damage ladders are often the reasons for this.

Thus, the answer in the above statement is False because ladders are required to be inspected for visible defects prior to the first use of each work shift and after any occurrence that could affect their safety.

4 0

3 years ago

First Aid is used for all of the stated reason except:

nekit [7.7K]

prevent injury

Explanation:

one is already injured Soo there's no protection there

4 0

3 years ago

IV. Activities:

Olin [163]

The OBLIQUE different objects below are the1, 3, and 6 in the picture given below.

<h3>What is an OBLIQUE object ?</h3>

A projective drawing of which the frontal strains are given in proper proportions and members of the family and all others at appropriate angles aside from ninety levels without regard to the guidelines of linear perspective.

Oblique drawings are drawn with one plane (front) of the item parallel to the drawing surface. The aspect, or difference seen a part of the item is normally drawn at 30◦ or 45◦. Note that simplest the aspect is on an angle. In many instances, those sorts of drawings aren't interested in scale.