A. The the rollercoaster's Gravitational potential energy is 509600 J
B. The rollercoaster's kinetic energy is 509600 J
C. The rollercoaster's speed is 39.6 m/s
From the question given above,
PE = mgh
PE = 650 × 9.8 × 80
PE = 509600 J
Since the rollercoaster is descending from the hill, the potential energy at the top will be equal to the kinetic energy at the bottom.
Thus,
KE = PE = 509600 J
KE = ½mv²
509600 = ½ × 650 × v²
509600 = 325 × v²
Divide both side by 325
v² = 509600 / 325
Take the square root of both side
v = √(509600 / 325)
v = 39.6 m/s
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