Final answer:
Using the kinematic equation for uniformly accelerated motion, the rock's velocity after 4 seconds, thrown downward at an initial speed of -6.00 m/s, would be -45.2 m/s. However, this answer is not listed in the provided choices, indicating a possible error in the question or answer choices.
Step-by-step explanation:
If a rock is thrown downward with an initial speed of -6.00 m/s, the question asks what the rock's velocity will be after 4.00 seconds. To solve this, we can use the kinematic equation which is suitable for uniformly accelerated motion, and since we're dealing with gravity here, the acceleration a is -9.80 m/s² (the negative sign indicates that it's directed downwards). The kinematic equation that relates initial velocity, acceleration, and time is: v = vo + at, where:
- vo is the initial velocity
- a is the acceleration due to gravity
- t is the time elapsed
Plugging the known values into the equation we get the final velocity after 4.00 seconds as follows:
v = -6.00 m/s + (-9.80 m/s²)(4.00 s) = -6.00 m/s - 39.2 m/s = -45.2 m/s
However, since the possible answers provided do not include this value, it appears there might be a typo or error in the question or the answer choices. But based on the physics, the calculation indicates that the velocity would be -45.2 m/s after 4 seconds if thrown downwards with an initial speed of -6.00 m/s.