"To solve these problems, we can use the equations of motion under constant acceleration. The final velocity v when an object reaches the ground and the time t it takes to fall can be determined using the following equations:
1. v = u + at , where:
- u is the initial velocity (15 \, \text{m/s} in this case),
- a is the acceleration due to gravity (9.81 \, \text{m/s}^2 on Earth, 3.71 \, \text{m/s}^2 on the Moon),
- t is the time.
2. s = ut + \frac{1}{2}at^2 , where:
- s is the distance fallen (244 \, \text{m} in this case).
Given s = 244 , u = 15 , and values of a for Earth and Moon, we can find t by rearranging the second equation and solving using the quadratic formula.
Now, let's find the values for Earth:
Using the quadratic formula to find t for Earth, where a = 9.81 :
t = \frac{-u + \sqrt{u^2 + 2as}}{a}
t \approx \frac{-15 + \sqrt{15^2 + 2(9.81)(244)}}{9.81} \approx 5.69 \, \text{s}
Now, calculating the final velocity v for Earth:
v = 15 + (9.81)(5.69) = 70.80 \text{ m/s}
Next, let's find the values for the Moon:
Using the quadratic formula to find t for the Moon, where a = 3.71 :
t \approx \frac{-15 + \sqrt{15^2 + 2(3.71)(244)}}{3.71} \approx 8.12 \, \text{s}
Calculating the final velocity v for the Moon:
v = 15 + (3.71)(8.12) = 45.12 \text{ m/s}
\textbf{Answer:}
On Earth, the object will reach the ground with a speed of approximately 70.80 \, \text{m/s} and take approximately 5.69 seconds to fall.
On the Moon, the object will reach the ground with a speed of approximately 45.12 \, \text{m/s} and take approximately 8.12 seconds to fall."