Answer: When the concentration of nanosilver particles in water is increased, the population of Daphnia magna will decrease
Explanation:
The statement below that is the most likely testable hypothesis based on the information provided is that when there is an increase in the concentration of nanosilver particles in water, the population of Daphnia magna will decrease.
Since we are informed that the particles may decrease survival in many aquatic organisms, it simply means that an increase in the particles in water will bring about the decrease in the Daphnia magna, which is the tiny freshwater crustacean.
Work= force (N) x distance (m)
F= mass (kg) x acceleration (gravity; m/s^2)
for this question, your formula would be
Work= mass (kg) x acceleration (gravity) x distance (m)
a. F=20kg x 9.81 m/s^2 x6 m = 1177.2 J
b. F=25kg x 9.81 m/s^2 x3 m = 735.75 J
c. F=25kg x 9.81 m/s^2 x6 m = 1471.5 J
d. F=50kg x 9.81 m/s^2 x1 m = 490.5 J
Tip:
- If this was a timed test, you could save some time by just multiplying the mass (kg) in the question by the distance because 9.81 is a constant in the formula, you can ignore it (+you're not asked for the final answer). c would still be the largest number
- it would also help if you noticed:
- the distance in c is half that of b but the mass is the same. eliminate b because c is obviously bigger
- a and c have the same distance but 25 is greater than 20; eliminate a
