/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 47 A space probe is sent to the vic... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A space probe is sent to the vicinity of the star Capella, which is 42.2 light-years from the earth. (A light-year is the distance light travels in a year.) The probe travels with a speed of 0.9930c. An astronaut recruit on board is 19 years old when the probe leaves the earth. What is her biological age when the probe reaches Capella?

Short Answer

Expert verified
The astronaut's biological age upon reaching Capella is approximately 23.9 years.

Step by step solution

01

Identify the Relevant Concept

This exercise involves relativistic effects on time due to high-speed travel. Specifically, it requires the use of time dilation in Special Relativity to determine the biological age of the astronaut.
02

Formula for Time Dilation

Use the time dilation formula: \[ t' = \frac{t}{\sqrt{1 - \frac{v^2}{c^2}}} \]where \( t' \) is the proper time experienced by the astronaut (biological time), \( t \) is the time experienced on Earth, \( v \) is the velocity of the probe, and \( c \) is the speed of light.
03

Calculate the Earth Time

First, calculate the time it takes for the probe to reach Capella from the perspective of Earth. Since Capella is 42.2 light-years away, and the probe speed is \( 0.9930c \), the time taken according to Earth is:\[ t = \frac{42.2}{0.9930} \approx 42.487 \text{ years} \]
04

Calculate the Proper Time (Astronaut's Time)

Substitute the values into the time dilation formula to find the astronaut's time:\[ t' = \frac{42.487}{\sqrt{1 - 0.9930^2}} \approx \frac{42.487}{\sqrt{1 - 0.9861}} \approx \frac{42.487}{0.1155} \approx 4.904 \text{ years} \]
05

Determine Astronaut's Biological Age

The recruit starts the journey at 19 years old. Therefore, her biological age when reaching Capella is:\[ 19 + 4.904 = 23.904 \] After rounding, it is approximately 23.9 years.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Time Dilation
Time dilation is a fascinating concept in the world of physics, particularly within the realm of special relativity. This idea was first introduced by Albert Einstein, who showed that time is not an absolute measure but can vary depending on the relative velocity of an observer.
Time dilation refers to the phenomenon where time, as measured by an observer in a different inertial frame, moves slower compared to a stationary observer. This effect is most noticeable at speeds approaching the speed of light.
  • For example, in the context of our space probe traveling at 0.9930 times the speed of light, the time experienced by the passenger (astronaut) on the probe differs from the time experienced on Earth.
  • The formula used to describe this relationship is: \[t' = \frac{t}{\sqrt{1 - \frac{v^2}{c^2}}}\]where \( t' \) is the proper time experienced by the moving observer, \( t \) is the time in the stationary observer's frame (Earth), \( v \) is the velocity of the moving observer, and \( c \) is the speed of light.
  • This formula implies that as the velocity \( v \) becomes closer to \( c \), the denominator gets smaller, causing \( t' \) to decrease compared to \( t \).
Thus, for astronauts traveling at high speeds, aging occurs more slowly relative to those they left behind on Earth.
Relativistic Effects
Relativistic effects are crucial in understanding how objects behave at speeds that are significant compared to the speed of light. These effects become prominent in space travel scenarios, as in our example with the astronaut traveling to Capella.
Relativistic effects manifest mainly in three domains: length contraction, time dilation, and mass increase. However, for the purpose of our problem, the focus is on time dilation.
  • At nearly the speed of light, time dilation ensures that the astronaut feels less time passing on board the spaceship than the time calculated on Earth.
  • This difference can lead to various interesting and sometimes counterintuitive results, such as aging more slowly, as evidenced by the lower biological age of the astronaut by the journey's end.
  • Without accounting for these relativistic effects, calculations of time and distance in high-speed environments would be vastly inaccurate.
In situations like high-speed space travel, understanding relativistic effects is essential to accurately predict temporal experiences and changes.
Proper Time
Proper time is a fundamental concept in relativity that helps us understand how different observers in different frames measure the passage of time.
Proper time refers to the actual time interval measured by an observer as they travel along their worldline in spacetime. This is the time experienced by someone on a journey, such as our astronaut within the moving space probe traveling toward Capella.
  • In the context of the exercise, the proper time \( t' \) represents the amount of time the astronaut feels has passed according to her biological clock onboard the spaceship.
  • It is distinguished from the time experienced by an observer who is not moving with respect to the stars, termed as coordinate time \( t \). In this case, the time calculated on Earth.
  • Proper time is always less than or equal to the coordinate time for an observer in motion relative to a stationary observer.
Proper time allows us to make sense of the journey's duration experienced personally by the traveler, highlighting how speed can affect the perception of time itself.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Calculate the magnitude of the force required to give a 0.145-kg baseball an acceleration \(a =\) 1.00 m/s\(^2\) in the direction of the baseball's initial velocity when this velocity has a magnitude of (a) 10.0 m/s; (b) 0.900c; (c) 0.990c. (d) Repeat parts (a), (b), and (c) if the force and acceleration are perpendicular to the velocity.

Two particles in a high-energy accelerator experiment approach each other head-on with a relative speed of 0.890c. Both particles travel at the same speed as measured in the laboratory. What is the speed of each particle, as measured in the laboratory?

A proton has momentum with magnitude \(p_0\) when its speed is 0.400c. In terms of \(p_0\) , what is the magnitude of the proton's momentum when its speed is doubled to 0.800c?

The negative pion (\(\pi^-\)) is an unstable particle with an average lifetime of 2.60 \(\times\) 10\(^{-8}\)s (measured in the rest frame of the pion). (a) If the pion is made to travel at very high speed relative to a laboratory, its average lifetime is measured in the laboratory to be 4.20 \(\times\) 10\(^{-7}\) s. Calculate the speed of the pion expressed as a fraction of c. (b) What distance, measured in the laboratory, does the pion travel during its average lifetime?

A particle has rest mass 6.64 \(\times\) 10\(^{-27}\) kg and momentum 2.10 \(\times\) 10\(^{-18}\) kg \(\bullet\) m/s. (a) What is the total energy (kinetic plus rest energy) of the particle? (b) What is the kinetic energy of the particle? (c) What is the ratio of the kinetic energy to the rest energy of the particle?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.