The correct answer is A. Lumen
This is the so called energy of light measurement. Other mentioned measurements are used for different things such as measuring light over an area of space or similar.
-16 km/hr/sec because she slows down 4 km/hr (12 - 8) in 0.25 seconds. in one second (0.25 sec * 4) she would slow down by 16 km/hr (4 * 4). it’s negative acceleration because she’s slowing down
Answer:
38.8 m/s
Explanation:
Force F(x) = 6 - 2x + 6x²
work


W = mv²/2=7v²/2 = 3.5v² = 5261
v = 38.8 m/s