Answer:
42.11 years old
Explanation:
Given that:
In 2000, a 20-year-old astronaut left Earth to explore the galaxy; her spaceship travels at 2.5 x 10^8 m/s. She returns in 2040
To find her age we use:
![\Delta t_m=\frac{\Delta t_s}{\sqrt{1-\frac{v^2}{c^2} } }\\](https://tex.z-dn.net/?f=%5CDelta%20t_m%3D%5Cfrac%7B%5CDelta%20t_s%7D%7B%5Csqrt%7B1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%20%7D%20%7D%5C%5C)
Δtm is time interval for the observer stationary relative to the sequence of
events = 2040 - 2000 = 40 years
Δts is is the time interval for an observer moving with a speed v relative to the sequence of event
v = velocity = 2.5 x 10^8 m/s
c = speed of light = 3 x 10^8 m/s
![\Delta t_s=\Delta t_m}{\sqrt{1-\frac{v^2}{c^2} } }\\\Delta t_s=40\sqrt{1-\frac{(2.5*10^8)^2}{(3*10^8)^2}}\\\Delta t_s=22.11\ yr](https://tex.z-dn.net/?f=%5CDelta%20t_s%3D%5CDelta%20t_m%7D%7B%5Csqrt%7B1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%20%7D%20%7D%5C%5C%5CDelta%20t_s%3D40%5Csqrt%7B1-%5Cfrac%7B%282.5%2A10%5E8%29%5E2%7D%7B%283%2A10%5E8%29%5E2%7D%7D%5C%5C%5CDelta%20t_s%3D22.11%5C%20yr)
Here age in 2000 is 20 year, therefore when she appear she would be 20 year + 22.11 year = 42.11 years old
Given,
A player kicks a soccer hits at an angle of 30° at a speed of 26 m/s
We can resolute the trajectory of soccer into horizontal and vertical components.(Please see the attached file)
We can have,
Horizontal velocity component of ball= 26cos(30°) = 26×(√3÷2) = 22.51 m/s
And vertical velocity component of ball = 26sin(26°) = 26×(1÷2) = 13 m/s
Answer:
By Applying pressure to the brakes
Explanation:
Driving cars through deep water that is more than 10cm can make the cars to float. Most modern cars are usually water- tight so they can start to float through water that is about 30cm deep, fast moving water is very powerful so one needs to be very careful when driving.
If the brakes are wet test them by pressing or tapping on them gently.
You can as well dry brakes by driving in low gear and applying pressure to the brakes.