To solve the problem of two bodies thrown simultaneously from a tower with the same initial velocity, one upwards and the other downwards, we need to analyze their motions separately and then find the distance between them after a time \( t \).
Understanding the Motion of Each Body
Let's denote the initial velocity of both bodies as \( v \). The body thrown upwards will experience a deceleration due to gravity, while the body thrown downwards will accelerate under the same gravitational force. We'll use the following variables:
- g: Acceleration due to gravity (approximately \( 9.81 \, \text{m/s}^2 \))
- h: Height of the tower
- t: Time elapsed since the bodies were thrown
Body Thrown Upwards
The position of the body thrown upwards can be described by the equation of motion:
y_{up} = h + vt - \frac{1}{2}gt^2
Here, \( h \) is the initial height of the tower, \( vt \) is the distance traveled upwards, and \( \frac{1}{2}gt^2 \) accounts for the downward displacement due to gravity.
Body Thrown Downwards
For the body thrown downwards, the equation of motion is:
y_{down} = h - vt - \frac{1}{2}gt^2
In this case, \( h \) is still the initial height, but the body moves downwards, so we subtract the distance traveled downwards due to its initial velocity and the effect of gravity.
Calculating the Distance Between the Two Bodies
To find the distance between the two bodies after time \( t \), we need to calculate the difference in their positions:
Distance = |y_{up} - y_{down}|
Substituting the equations we derived:
Distance = |(h + vt - \frac{1}{2}gt^2) - (h - vt - \frac{1}{2}gt^2)|
When we simplify this expression, we notice that the terms involving \( h \) and \( \frac{1}{2}gt^2 \) cancel out:
Distance = |vt + vt| = |2vt| = 2vt
Final Result
Thus, the distance between the two bodies after time \( t \) is:
Distance = 2vt
This result shows that the distance between the two bodies increases linearly with time and is directly proportional to their initial velocity. The faster they are thrown, the greater the distance between them after the same amount of time.