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Will a steel structure still be standing at a temperature past its critical temperature? Or will it be unsafe?
The critical temperature of steel is 550 degrees.
The temperature for cellouslic materials can be given by the formula:
T=20+345〖log〗_10 (8t+1)
Where T is the fire resistance and t is the temperature of the furnance. if t is 550 degrees (critical temperature of steel), this gives a fire resistance of approx 5mins which is too low. So i used a different guidance document
For unprotected steels especially the temperature can be given by:
T=0.54(θs-50)(〖Hp/A〗^(-0.6) )
Where T is the fire resistance, θs is the temperature of the furnance and Hp/A is the section factor of the beam. Taking a 43kg 254mmx146mm beam which is exposed on 3 sides for example, the section factor is 170. taking θs as 550 degrees and Hp/A as 170, this gives approximately 12.4minutes of fire resistance which is also too low.
So what Im trying to ask, is that will a steel beam ultimately collapse at 550 degrees or is 550degrees the temperature a steel beam would start to bend. If so what temperature does a steel structure completely fail and cause a structure to collapse. Any help would be appreciated. Thank you.
2 AnswersEngineering3 years agoShould I buy a SEIKI 39 inch 4k TV?
I want to use this 4k TV for gaming on my PS4. If I buy a HDMI 2.0 cable the TV will have a 60hz refresh rate apparently. Hence should I bother buy this 4k TV. It's a very cheap price compared to the others
Or should I just settle with a 1080p LED TV. I'm still undecided
2 AnswersPlayStation6 years agoShould I bother buy a 4k TV or get a 1080p TV for my PS4?
I got a PS4 so I was thinking of buying a 4K TV but I've heard that PS4 and XB1 aren't capable of rendering games at 4K so is there any point of buying a 4K TV. Should i just buy a 1080p TV and wait for the next gen consoles to come out before i buy a 4k TV
5 AnswersPlayStation6 years agoNatural angular frequency question, what's the mass of block B?
1 AnswerPhysics6 years ago
What is the natural frequency of this system?
pulleys are massless and they oscillate towards the equilibrium positon?
The mass of the block is 26kg
The radius of each pulley is 0.9m
The stiffness constant is 100N/m
Please help?
3 AnswersPhysics6 years agoDoes anyone know how to derive the flexural strain?
Flexural strain is 6bd/L^2
b=width
d=depth
L=length
1 AnswerEngineering6 years ago
Where have i gone wrong?
if the coefficient of friction is and the radius of the cylinder is 2 m, calculate the critical value of the cylinder's rotational speed to ensure that the people don't slip down when the floor moves away from them?
r=2.4m u=0.5, g=9.81 etc
a=ug, a=rw^2, rw^2=ug w^2=ug/r
w=sqrt(ug/r), w=sqrt(0.5x9.81/2.4)
w=1.43
but this is wrong
need help
1 AnswerPhysics6 years ago
Need help with mechanics question?
m1=78kg
m2=120kg
I got the acceleration as -9.81m/s^2 but i was wrong. The double pulley system is confusing me a bit
2 AnswersMathematics6 years ago
What I'm i doing wrong here?
The question asks for the system acceleration and the tension in the cable
So when approaching this question I did this
F is the force, Ff is the friction force, N is the normal reaction force, T is the tension
Fx=30cos24
Fy=30sin24
N1=4g-Fy
N2=3g
Ff1=0.57(N1)
Ff2=0.57(N2)
so for m1
30cos24-T-Ff1=4a
and for m2
T-Ff2=3a
so
30cos24-Ff1-Ff2=7a
a=30cos24-Ff1-Ff2/7
a=-0.683
T=14.7N?????
I think I've made a mistake somewhere because my acceleration is negative any help
2 AnswersPhysics6 years ago
How do i answer this weird mechanics question?
Ronald, a clever kid, has designed a snowball launcher to get his snowballs over a neighbor's fence and into their yard. The fence is 17.54 m high (these neighbors are very unsociable), the launcher is positioned 67.4 m from the wall, and the neighbor's son, Rupert, is sitting on the ground 79.4 m from Ronald (12 m from the wall). What is the only allowable launch angle that, with a sufficient launch velocity, will cause the snowball to just miss hitting the top of the wall and then land on Rupert?
2 AnswersPhysics6 years ago
Strange mechanics question update! Need help with this weird question?
A worker is dragging a large drum of mass m through the use of a pulley arrangement. If she’s able to move to the left at 2 m/s, how fast will the mass move to the right?
1 AnswerPhysics6 years agoStrange mechanics question which is bothering me, need a bit of help?
A worker is dragging a large drum of mass m through the use of a pulley arrangement. If she’s able to move to the left at 2 m/s, how fast will the mass move to the right?
2 AnswersPhysics6 years agoAnother strange mechanics question i need help with?
convert er and etheta into vector components for velocity and acceleration
velocity er: 0.7er and 0.45etheta
acceleration er: 0.278er and 043theta
I don't know how to convert them into cartesian coordinates which is in the form xi+yj
Here are the formulas
er=costheta(i)+sintheta(j)
etheta=-sintheta(i)+costheta(j)
theta in this example is pi/6. So please work in radians. Well many thanks in advance
1 AnswerMathematics6 years agoHelp with mechanics question? For some reason I can't do it :?
A ceiling fan is moving at a constant rotation rate and makes one revolution in 0.9 s. The distance from the fan’s center to the outermost tip of a blade is 1.1 m. A fly F is resting right at the tip. What is the magnitude of the fly's acceleration?
1 AnswerPhysics6 years ago
Need help with a mechanics question?
I don't know how they get these answers.
R=3.8kN
Theta= 338 degrees
Showing your working out when tackling this question will be much appreciated. Question is in the photo. Good luck!
1 AnswerMathematics6 years agoPhysics statics question help?
Find the friction force F acting on the block if P = 673 N.
Additional information
P is pushing the block upwards and is inclined at a angle of 20 degrees
The mass of the block is 117kg
The surface is inclined at 16 degrees
The friction force acts down the plane.
Good luck
1 AnswerPhysics6 years agoHow do i solve this simultaneous equation?
i was dealing with a question and got these 2 simultaneous equations where Sine and cosine angles are in degrees. Well the problem i came across is how to solve these and where to go from here. Help! and good luck.
Ta(cos52)+Tb(sin23)=244
Tb(sin23)-Ta(sin52)=74.6
Find Ta and Tb?
1 AnswerMathematics6 years agoWill a hard factory reset on the xbox fix the E68 error?
When i put in my harddrive the xbox loads slow. Games take forever to load and the xbox restarts on me and then loads up with a error E68 after more than 30 minutes of gameplay.
When the harddrive isn't inserted in the xbox this doesn't happen and it loads smoothly. What do i do?
Will a hard factory reset on the harddrive fix my problem.
1 AnswerXbox6 years ago
