what can be done to prevent bridges from collapsing? ( give at least two examples)

1. A flywheel is suspended by resting the inside of the rim on a horizontal knife edge so that the wheel can swing in a vertical

sammy [17]

Answer: A fly wheel having a mass of 30kg was allowed to swing as pendulum about a knife edge at inner side of the rim as shown in figure.

Explanation:

8 0

2 years ago

Calculate the availability of a system where the mean time between failures is 900 hours and the mean time to repair is 100 hour

Debora [2.8K]

Answer:

The availability of system will be 0.9

Explanation:

We have given mean time of failure = 900 hours

Mean time [to repair = 100 hour

We have to find availability of system

Availability of system is given by $\frac{mean\time\ of\ failure}{mean\ time\ of\ failure+mean\ time\ to\ repair}$

So availability of system $=\frac{900}{900+100}=\frac{900}{1000}=0.9$

So the availability of system will be 0.9

7 0

2 years ago

The time delay of a long-distance call can be determined by multiplying a small fixed constant by the number of communication li

aliina [53]

Answer:

We can compute the diameter of the tree T by a pruning procedure, starting at the leaves (external nodes).

Remove all leaves of T. Let the remaining tree be T1.
Remove all leaves of T1. Let the remaining tree be T2.
Repeat the "remove" operation as follows: Remove all leaves of Ti. Let remaining tree be Ti+1.
When the remaining tree has only one node or two nodes, stop! Suppose now the remaining tree is Tk.
If Tk has only one node, that is the center of T. The diameter of T is 2k.
If Tk has two nodes, either can be the center of T. The diameter of T is 2k+1.

Explanation:

We can compute the diameter of the tree T by a pruning procedure, starting at the leaves (external nodes).

Remove all leaves of T. Let the remaining tree be T1.
Remove all leaves of T1. Let the remaining tree be T2.
Repeat the "remove" operation as follows: Remove all leaves of Ti. Let remaining tree be Ti+1.
When the remaining tree has only one node or two nodes, stop! Suppose now the remaining tree is Tk.
If Tk has only one node, that is the center of T. The diameter of T is 2k.
If Tk has two nodes, either can be the center of T. The diameter of T is 2k+1.

4 0

3 years ago

1. A _____ is applied to a wall or roof rafters to add strength and keep the building straight and plumb.

PSYCHO15rus [73]

Answer:

A force must s applied to a wall or roof rafters to add strength and keep the building straight and plumb

7 0

2 years ago

A thick aluminum block initially at 26.5°C is subjected to constant heat flux of 4000 W/m2 by an electric resistance heater whos

Yanka [14]

Given Information:

Initial temperature of aluminum block = 26.5°C

Heat flux = 4000 w/m²

Time = 2112 seconds

Time = 30 minutes = 30*60 = 1800 seconds

Required Information:

Rise in surface temperature = ?

Answer:

Rise in surface temperature = 8.6 °C after 2112 seconds

Rise in surface temperature = 8 °C after 30 minutes

Explanation:

The surface temperature of the aluminum block is given by

$T_{surface} = T_{initial} + \frac{q}{k} \sqrt{\frac{4\alpha t}{\pi} }$

Where q is the heat flux supplied to aluminum block, k is the conductivity of pure aluminum and α is the diffusivity of pure aluminum.

After t = 2112 sec:

$T_{surface} = 26.5 + \frac{4000}{237} \sqrt{\frac{4(9.71\times 10^{-5}) (2112)}{\pi} }\\\\T_{surface} = 26.5 + \frac{4000}{237} (0.51098)\\\\T_{surface} = 26.5 + 8.6\\\\T_{surface} = 35.1\\\\$

The rise in the surface temperature is

Rise = 35.1 - 26.5 = 8.6 °C

Therefore, the surface temperature of the block will rise by 8.6 °C after 2112 seconds.

After t = 30 mins:

$T_{surface} = 26.5 + \frac{4000}{237} \sqrt{\frac{4(9.71\times 10^{-5}) (1800)}{\pi} }\\\\T_{surface} = 26.5 + \frac{4000}{237} (0.4717)\\\\T_{surface} = 26.5 + 7.96\\\\T_{surface} = 34.5\\\\$

The rise in the surface temperature is

Rise = 34.5 - 26.5 = 8 °C

Therefore, the surface temperature of the block will rise by 8 °C after 30 minutes.

5 0

2 years ago

￼ what can be done to prevent bridges from collapsing? ( give at least two examples)￼

what can be done to prevent bridges from collapsing? ( give at least two examples)