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3 years ago

Why are bridges declared unsafe after a long use

1 answer:

lina2011 [118]3 years ago

8 0

After it's long use, the bridge continuously undergoes through alternating strains. in result, the elastic strength of the bridge gets reduced. while the process goes on the bridge makes elastic fatigue and a permanent change happens which makes it collapse which is the reason why bridges are declared unsafe after a long use :)

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Express force in terms of base units

MariettaO [177]

<h2><u>Answer:</u></h2>

<u></u>

<u>Force = kgm/s² ⟶ Newton</u>

<h2><u>Explanation:</u></h2>

<u></u>

According to the formula we've learnt,

Force = mass × acceleration.

To find force in terms of base units, we must first identify the base SI units of mass & acceleration.

Base SI unit of mass = kg (kilogram)

Base SI unit of acceleration = m/s² (meter per second squared)

So, the base unit of force is,

Force = mass × acceleration.

Force = kg × m/s²

<u>Force = kgm/s² ⟶ Newton</u>

________________

Hope it helps!

$\mathfrak{Lucazz}$

4 0

2 years ago

A hot-air balloon is ascending at the rate of 10 m/s and is 74 m above the ground when a package is dropped over the side. (a) H

Reika [66]

Answer:

The answer to your question is:

a) t1 = 2.99 s ≈ 3 s

b) vf = 39.43 m/s

Explanation:

Data

vo = 10 m/s

h = 74 m

g = 9.81 m/s

t = ? time to reach the ground

vf = ? final speed

a) h = vot + (1/2)gt²

74 = 10t + (1/2)9.81t²

4.9t² + 10t -74 = 0 solve by using quadratic formula

t = (-b ± √ (b² -4ac) / 2a

t = (-10 ± √ (10² -4(4.9(-74) / 2(4.9)

t = (-10 ± √ 1550.4 ) / 9.81

t1 = (-10 + √ 1550.4 ) / 9.81 t2 = (-10 - √ 1550.4 ) / 9.81

t1 = (-10 ± 39.38 ) / 9.81 t2 = (-10 - 39.38) / 9.81

t1 = 2.99 s ≈ 3 s t2 = is negative then is wrong there are

no negative times.

b) Formula vf = vo + gt

vf = 10 + (9.81)(3)

vf = 10 + 29.43

vf = 39.43 m/s

4 0

3 years ago

"what information does the slope of the line give you when graphing the pressure versus 1/volume at constant temperature for 1 m

Rashid [163]

Hello!

The slope of the line given by graphing pressure vs 1/Volume at constant temp for one mole of gas will give you the value for nRT from equation PV=nRT

So set nRT=slope and take the constant number mole of gas and the constant temp and solve for R the universal gas constant. You arm for pressure and litters for volume to get R in units of L*atm/mol*k

Hope this helps you! Thanks!!

6 0

3 years ago

A spectral line from a star is observed to have a wavelength of 656.5 nm. The rest wavelength of this line is 656.8 nm. (a) What

nignag [31]

Answer:

speed of star is 1.37 × $10^{5}$ m/s