can u tell me what formula i should be using to answer this question?
If a stone falls past a bird on a ledge moving at 4 m/s, how fast will the stone be movingjust before it hits the ground below 9 seconds later?
A. 92.2 m/s
B. 48.2 m/s
C. 352.8 m/s
D. 36 m/s
To answer this question, you need to use the formula for kinematics in vertical motion. The formula you need is:
v_f = v_i + gt
Where:
v_f is the final velocity of the stone
v_i is the initial velocity of the stone (which is 0 since it was dropped)
g is the acceleration due to gravity (approximately 9.8 m/s^2)
t is the time it takes for the stone to fall (given as 9 seconds)
Now let's plug in the values:
v_f = 0 + (9.8 m/s^2)(9 s)
v_f = 88.2 m/s
Therefore, the speed of the stone just before hitting the ground is 88.2 m/s.
None of the answer choices provided exactly match 88.2 m/s. However, option A (92.2 m/s) is the closest answer.