Total time elapsed is =8.2y
The starting event is the astronaut leaving Earth. The finishing event is the astronaut arriving at the star system. The time between these events on Earth is:
Δt=3.9ly/0.9c
Δt=4.3y
For the astronaut, two events occur at the same position and can be measured with just one clock. Hence,
Δτ
![= \sqrt{1 - \frac{v {}^{2} }{c {}^{2} } } \times Δt](https://tex.z-dn.net/?f=%20%3D%20%20%5Csqrt%7B1%20-%20%20%5Cfrac%7Bv%20%7B%7D%5E%7B2%7D%20%7D%7Bc%20%7B%7D%5E%7B2%7D%20%7D%20%20%7D%20%20%5Ctimes%20%CE%94t)
Δτ
![= \sqrt{1 - ( \frac{0.9c}{c} ) {}^{2} } \times (4.3y)](https://tex.z-dn.net/?f=%20%3D%20%20%5Csqrt%7B1%20-%20%28%20%5Cfrac%7B0.9c%7D%7Bc%7D%20%29%20%7B%7D%5E%7B2%7D%20%7D%20%20%5Ctimes%20%284.3y%29)
Δτ=1.8ly
The total elapsed time is:
T elapsed=Δt+3.9
T elapsed=4.3+3.9
T elapsed=8.2y
learn more about time from here: brainly.com/question/28208983
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<span>1) at rest his
weight is 840 N
=> 840N = mass * g => mass = 840 N / g = 840 N / 9.8 m/s^2 = 85.7 kg
2) as the elevator rises, his weight increases to 1050 N,
The reading of the scale is the norma force of it over the body of the person.
And the equation for the force is: Net force = mass * acceleration = normal force - weight at rest
=> mass * acceleration = 1050 N - 840 N = 210 N
acceleration = 210 N / mass = 210 N / 85.7 kg = 2.45 m/s^2 (upward)
3) when the elevator slows to a stop at the 10th
floor, his weight drops to 588 N
=> mass * acceleration = 588 N - 840 N = - 252 N
=> acceleration = - 252 N / 85.71 kg = - 2.94 m / s^2 (downward)
Answer:
Acceleration at the beginning of the trip 2.45 m/s^2 upward
Acceleration at the end of the trip 2.94 m/s^2 downward
</span>
"Oscilloscope" can be used to show the shape of a sound wave
Hope this helps!
Answer:
C. Burning coal tends to harm the environment more than using solar panels.
Explanation:
When coal is burned, it reacts with the oxygen in the air. This reaction converts the stored potential energy, which turns into thermal energy, which is released as heat. But it also produces methane and carbon dioxide which is released into the air.
Julia walks from the park, which is six blocks east of her house, to the store, which is three blocks east of her house. Julia walks for 5 minutes. This walk's average speed will be 1.2 blocks per minute. Option B is correct.
<h3>What is displacement?</h3>
Displacement is defined as the shortest distance between the two points. Distance is the horizontal length covered by the body. While displacement is the shortest distance between the two points.
Displacement is a vector quantity .its unit is m.
The average velocity on this walk will be;
![\rm v_{avg}= \frac{d}{t} \\\\ \rm v_{avg}= \frac{6 \ block+ 3 \ block }{5 \ minute } \\\\ v_{avg}=1.4 \ block /min](https://tex.z-dn.net/?f=%5Crm%20v_%7Bavg%7D%3D%20%5Cfrac%7Bd%7D%7Bt%7D%20%5C%5C%5C%5C%20%5Crm%20v_%7Bavg%7D%3D%20%5Cfrac%7B6%20%5C%20block%2B%203%20%5C%20block%20%7D%7B5%20%5C%20minute%20%7D%20%5C%5C%5C%5C%20v_%7Bavg%7D%3D1.4%20%20%5C%20block%20%2Fmin)
Hence option B is correct.
To learn more about displacement refer to the link; brainly.com/question/10919017
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