Answer:
n = 1810
A = 25 mm
Explanation:
Given:
Lateral force amplitude, F = 25 N
Frequency, f = 1 Hz
mass of the bridge, m = 2000 kg/m
Span, L = 144 m
Amplitude of the oscillation, A = 75 mm = 0.075 m
time, t = 6T
now,
Amplitude as a function of time is given as:

or amplitude for unforce oscillation

or

or

Now, provided in the question Amplitude of the driven oscillation

the value of the maximum amplitude is obtained
thus,

Now, for n people on the bridge
Fmax = nF
thus,
max amplitude

or
n = 1810
hence, there were 1810 people on the bridge
b)
since the effect of damping in the millenium bridge is 3 times
thus,
b=3b
therefore,

or

or

or
A = 0.025 m = 25 mm
Answer:
The maximum mass the bar can support without yielding = 32408.26 kg
Explanation:
Yield stress of the material (
) = 200 M Pa
Diameter of the bar = 4.5 cm = 45 mm
We know that yield stress of the bar is given by the formula
Yield Stress = 
⇒
=
---------------- (1)
⇒ Area of the bar (A) =
×
⇒ A =
× 
⇒ A = 1589.625 
Put all the values in equation (1) we get
⇒
= 200 × 1589.625
⇒
= 317925 N
In this bar the
is equal to the weight of the bar.
⇒
=
× g
Where
is the maximum mass the bar can support.
⇒
= 
Put all the values in the above formula we get
⇒
= 
⇒
= 32408.26 Kg
There fore the maximum mass the bar can support without yielding = 32408.26 kg
Answer:
The electrostatic force is the force that exists between electrically charged particles or objects at rest.
Answer:
367.57 nm
Explanation:
Given that the speed of the light in certain material is 0.6310 times the speed of light in vacuum.
Speed of light in vacuum = 3×10⁸ m/s
Speed of the light in that material = 0.6310×3×10⁸ m/s = 1.893×10⁸ m/s
The frequency of the light does not change but the wavelength of the light changes with change in the speed when light travels from one medium to another.
Thus, frequency = 5.15×10¹⁴ Hz
Using,
c = frequency × Wavelength
Wavelength = c / frequency = (1.893×10⁸ m/s) / (5.15×10¹⁴ Hz) = 367.57×10⁻⁹ m
Also,
1 nm = 10⁻⁹ m
<u>So, wavelength = 367.57 nm</u>
Answer:
Janna levin is a cosmologist and professor at physics.
She is an american by race
She was the presenter of Nova feature Black hole Apocalypse and has writtenany science non-fiction books
www.jannalevin.com is her own page where u get her correct info and bio