(a) How many kilometers are there in one light year (1 ly)?

A light-year is the distance light travels in a vacuum over the course of one year. To calculate this distance, we can use the speed of light and the duration of one year.

• The speed of light in a vacuum, denoted as $c$, is approximately $299,792,458$ meters per second ($m/s$).
• One year has approximately $365.25$ days to account for leap years.

Let's break it down:

$\text{1 year} = 365.25 \, \text{days} \times 24 \, \text{hours/day} \times 60 \, \text{minutes/hour} \times 60 \, \text{seconds/minute}$

This gives the total number of seconds in one year.

Then, to get the distance:

$\text{Distance} = \text{speed of light} \times \text{time in seconds}$

Finally, convert this distance from meters to kilometers (since there are 1,000 meters in a kilometer).

(b) What is 1 ly in meters?

To calculate 1 light-year in meters, simply multiply the speed of light in meters per second by the total number of seconds in one year (calculated in part a).

$1 \, \text{light year in meters} = c \times \text{number of seconds in a year}$

(c) How many meters are in a kilometer?

There are 1,000 meters in 1 kilometer. This is a direct conversion factor.

Velocity Relation to Distance and Time

The formula that relates velocity to distance and time is:

$\text{Velocity} = \frac{\text{Distance}}{\text{Time}}$

Where:

• Velocity ($v$) is how fast something is moving,
• Distance ($d$) is how far the object has traveled,
• Time ($t$) is the time it took to travel that distance.

Velocity is a vector quantity, meaning it has both magnitude and direction. Speed, which is the magnitude of velocity, is often used in similar contexts.

Would you like to see the full calculation for the light-year conversion?

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5 Related Questions:

1. What is the total number of seconds in a day?
2. How would the distance of a light year change if light traveled at half its speed?
3. What is the relationship between speed, velocity, and acceleration?
4. Can velocity be negative, and if so, what does it mean in terms of motion?
5. How can we measure astronomical distances using other units besides light-years?

Tip:

Always ensure that your units are consistent when solving physics-related problems, especially with velocity, distance, and time.