A student discovers a comet heading toward the Sun. The student records the initial distance from the Sun as 'd' while recording the initial mass of the comet as 'm' which resulted in a gravitational force of 'F'. Further observation of the comet shows that as it reaches a positon d/2, the mass of the comet has been reduced to 1/3 of its original mass. Which expression best represents the value of the gravitational force at d/2? A. F/3
B. 2F/3
C. 4F/3
D. 9F/2

Astudent creates a model of a closed ecosystem by filling a glass tank half full with water, then adding 10 snails and two small aquatic plants. the next day, all the snails are dead. what is the most likely cause of their death?

The frequencies refer to the sample data collected from a population of interest when performing a hypothesis test comparing two or more population proportions.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.