Final answer:
The final velocity of a rock thrown downwards with an initial velocity of -13.0 m/s and falling an additional 5.10 meters under gravity is -16.4 m/s.
Step-by-step explanation:
The question involves kinematics, specifically calculating the final velocity of an object in free fall under the influence of gravity. According to the given information, if the body had an initial speed of -13.0 m/s and it is subject to an acceleration due to gravity -9.8 m/s², we use the kinematic equation v² = vo² + 2a(y - yo) to calculate the final velocity after falling -5.10 meters.
Plugging the given values into the equation, we get v² = (-13.0 m/s)² + 2(-9.80 m/s²)(-5.10 m - 0 m) = 268.96 m²/s². Taking the square root, we find v = ±16.4 m/s. Given the direction of gravity and the initial velocity, the negative root applies, therefore the final velocity is v = -16.4 m/s.
To construct a word problem using this information, we can state:
'A rock is thrown downwards from a cliff with an initial speed of 13.0 m/s. As it falls under gravity, with no other forces acting upon it such as air resistance, how fast is the rock going after it falls an additional 5.10 meters?'