Question

The rock falls from the distance of 15 m before it hits the water. Calculate its kinetic energy just before hitting the water. Show your working

Answer 1

Answer:

8.57m

Explanation:

v²=u²+2as

then1/2mv²

Answer 2

Answer:

$k.e = \frac{1}{2} m {v}^{2} \\ {v}^{2} = {u}^{2} + 2gs \\ {v}^{2} = 0 + (2 \times 9.8 \times 15) \\ v = 17.1 \: m {s}^{ - 1} \\ k.e = \frac{1}{2} \times m \times {17.1}^{2} \\ = 147m \: joules \\ m \: is \: mass$