an elevator is moving up at a rate of one meter per second. the elevator is now at the street level. when was the elevator five meters below street level? when will the elevator be 10 meters above street level?
Just think about it.
Every second it travels 1 meter.
So, 5 seconds ago it was down 5 meters.
now think forward in time for 120 meters above.
Math
To determine when the elevator was five meters below street level, we can use the information that the elevator is moving up at a rate of one meter per second. Since we know the elevator is currently at street level, we can set up an equation to solve for the time it took the elevator to reach five meters below street level.
Let's use the variable 't' to represent time in seconds. We can set up the following equation:
-5 = 0 - 1t
We subtracted 5 from 0 because the elevator started at street level and was 5 meters below it. The negative sign indicates that the elevator was moving downwards. Solving for 't' gives us:
t = 5 seconds
Therefore, the elevator was five meters below street level 5 seconds ago.
Next, let's determine when the elevator will be 10 meters above street level. Using the same information that the elevator is moving up at a rate of one meter per second, we can set up another equation:
10 = 0 + 1t
We added 10 to 0 because we want to find the time when the elevator is 10 meters above street level. Solving for 't' gives us:
t = 10 seconds
Therefore, the elevator will be 10 meters above street level in 10 seconds.
To find out when the elevator was five meters below street level and when it will be 10 meters above street level, we need to determine the time it takes for the elevator to reach these positions.
Let's assume that the street level is at position 0, and any position below the street level is considered negative.
1. Finding when the elevator was five meters below street level:
Since the elevator is moving up at a rate of one meter per second, we can calculate the time it takes for the elevator to reach five meters below street level using the equation:
Time = Distance / Rate of Change
Time = -5 meters / 1 meter per second
Time = -5 seconds
Therefore, the elevator was five meters below street level five seconds ago.
2. Finding when the elevator will be 10 meters above street level:
Following the same logic, we can calculate the time it takes for the elevator to reach ten meters above street level using the equation:
Time = Distance / Rate of Change
Time = 10 meters / 1 meter per second
Time = 10 seconds
Therefore, the elevator will be 10 meters above street level in ten seconds from now.