Answer:
Sonia O'Sullivan (born 28 November 1969) is an Irish former track and field athlete. She won a gold medal in the 5000 metres at the 1995 World Championships, and a silver medal in the 5000 metres at the 2000 Olympic Games.[1] Her 2000 m world record of 5:25.36, set in 1994 stood until 2017.[2]
O'Sullivan first came to prominence when winning the 1500 m at the 1991 Universiade, before going on to finish fourth in the 3000 m final at the 1992 Olympic Games. She then won a silver medal in the 1500 m at the 1993 World Championships. She was the favourite for the 5000 m title at the 1996 Olympic Games but dropped out of the final due to illness. As well as her 1995 World title, she won three gold medals at the European Championships, in the 3000 m (1994), 5000 m (1998) and 10,000 m (1998), and is a two-time World Cross Country Champion.
O'Sullivan won silver medals in the 5000 m and 10,000 m at the 2002 European Championships, and competed at her fourth Olympic Games in 2004. She is known for her dramatic kick, clocking 28-second final 200 m splits in some of her races.[3]
She is the one of two women (the other Tirunesh Dibaba) who won the short and long course World Cross Country title at the same championship (1998 in Marrakesh).[4]
you can find from here
Answer: 3217.79 hours.
Explanation:
Given, A 140 lb. climber saved her potential energy as she descended from Mt. Everest (Elev. 29,029 ft) to Kathmandu (Elev. 4,600 ft).
Power = 0.4 watt
Mass of climber = 140 lb
= 140 x 0.4535 kg [∵ 1 lb= 0.4535 kg]
⇒ Mass of climber (m) = 63.50 kg
Let ![h_1=29,029\ ft= 8848.04\ m\ \ \ \ [ 1 ft=0.3048\ m ]](https://tex.z-dn.net/?f=h_1%3D29%2C029%5C%20ft%3D%208848.04%5C%20m%5C%20%5C%20%5C%20%5C%20%20%5B%201%20ft%3D0.3048%5C%20m%20%5D)
and 
Now, Energy saved =
![\text{Power}=\dfrac{\text{energy}}{\text{time}}\\\\\Rightarrow 0.4=\dfrac{4633620.91}{\text{time}}\\\\\Rightarrow\ \text{time}=\dfrac{4633620.91}{0.4}\approx11584052.28\text{ seconds}\\\\=\dfrac{11584052.28}{3600}\text{ hours}\ \ \ [\text{1 hour = 3600 seconds}]\\\\=3217.79\text{ hours}](https://tex.z-dn.net/?f=%5Ctext%7BPower%7D%3D%5Cdfrac%7B%5Ctext%7Benergy%7D%7D%7B%5Ctext%7Btime%7D%7D%5C%5C%5C%5C%5CRightarrow%200.4%3D%5Cdfrac%7B4633620.91%7D%7B%5Ctext%7Btime%7D%7D%5C%5C%5C%5C%5CRightarrow%5C%20%5Ctext%7Btime%7D%3D%5Cdfrac%7B4633620.91%7D%7B0.4%7D%5Capprox11584052.28%5Ctext%7B%20seconds%7D%5C%5C%5C%5C%3D%5Cdfrac%7B11584052.28%7D%7B3600%7D%5Ctext%7B%20hours%7D%5C%20%5C%20%5C%20%5B%5Ctext%7B1%20hour%20%3D%203600%20seconds%7D%5D%5C%5C%5C%5C%3D3217.79%5Ctext%7B%20hours%7D)
Hence, she can power her 0.4 watt flashlight for 3217.79 hours.
The displacement ........................
The question is incomplete. The complete question is :
A viscoelastic polymer that can be assumed to obey the Boltzmann superposition principle is subjected to the following deformation cycle. At a time, t = 0, a tensile stress of 20 MPa is applied instantaneously and maintained for 100 s. The stress is then removed at a rate of 0.2 MPa s−1 until the polymer is unloaded. If the creep compliance of the material is given by:
J(t) = Jo (1 - exp (-t/to))
Where,
Jo= 3m^2/ GPA
to= 200s
Determine
a) the strain after 100's (before stress is reversed)
b) the residual strain when stress falls to zero.
Answer:
a)-60GPA
b) 0
Explanation:
Given t= 0,
σ = 20Mpa
Change in σ= 0.2Mpas^-1
For creep compliance material,
J(t) = Jo (1 - exp (-t/to))
J(t) = 3 (1 - exp (-0/100))= 3m^2/Gpa
a) t= 100s
E(t)= ΔσJ (t - Jo)
= 0.2 × 3 ( 100 - 200 )
= 0.6 (-100)
= - 60 GPA
Residual strain, σ= 0
E(t)= Jσ (Jo) ∫t (t - Jo) dt
3 × 0 × 200 ∫t (t - Jo) dt
E(t) = 0
