Answer:
205.88 ×mass of rock
This problem uses the expression for the kinetic energy of a moving body. K.E = 1/2mv², where m = mass of rock and v = velocity of the rock.
Explanation:
We are requested to calculate the kinetic energy but in order to do sk we must first calculate the initial velocity at which the rock was thrown downwards.
Given the following: h = -7m (thrown downwards and assuming upwards to be positive), v = -23.43 (same reason) and g = 9.8m/s².
The full calculation can be found in the attachment below.
