Question

If you drop a rock off a cliff and it hits the ground 3 seconds later how tall is that cliff

Answer 1

The height of the cliff can be calculated using the equation for motion of falling objects under gravity, resulting in an estimated height of approximately 44.1 meters.

Step-by-step explanation:

To calculate the height of the cliff from which a rock is dropped and hits the ground 3 seconds later, you can use the physics equation for the motion of falling objects under gravity (neglecting air resistance). The formula is h = (1/2)gt², where h is the height, g is the acceleration due to gravity (approximately 9.8 m/s² on Earth), and t is the time taken to hit the ground.

Plugging in the values, we get h = (1/2) × 9.8 m/s² × (3 s)² = h = (1/2) × 9.8 × 9 = h = 44.1 meters. So, the cliff is approximately 44.1 meters tall.

Answer 2

Basic kinematics, negating drag and assuming ideal conditions, we use the equation:

d=vi*t+1/2*a*t^2

Since vi is 0 (we know this because you’re dropping it, not throwing it)…

…and the only acceleration acting on it is gravity, a=9.8 m/s^2…

…we get

d=1/2(9.8)(5)^2

Step-by-step explanation:

Some quick mental math tells us that this is about 125 m.

Plugging it in, we find it to be 122.5 m.