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A 6 kg rock falls from a cliff. Just before it hits the ground its speed is 24

m/s. From what height did it fall?
A. 29 m
B. 144 m
C. 72 m
D. 8 m

User Fariz Azmi
by
7.9k points

1 Answer

4 votes

Final answer:

By converting the kinetic energy into potential energy, we calculated the height from which a 6 kg rock fell to be approximately 29 meters before impacting the ground at 24 m/s. Therefore correct option is A

Step-by-step explanation:

To determine from what height a 6 kg rock falls when it hits the ground at 24 m/s, we use the equation for gravitational potential energy and kinetic energy.

The potential energy at the beginning (mgh) is equal to kinetic energy just before impact ½mv², where m is mass, g is the acceleration due to gravity (9.8 m/s²), h is the height, v is the velocity, and ½ is a constant representing 'one half'.

Solving for h, we rearrange the equation to h = v² / (2g).

Plugging in the values, h = (24 m/s)² / (2 * 9.8 m/s²)

= 576 / 19.6

= 29.4 m, which we can round to the nearest whole number, giving us a height of approximately 29 m.

User Shane H
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7.5k points