A pure substance that cannot be decomposed by ordinary chemical change. . Energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means.
Answer:
2000 J per second or 2kJ per second.
Explanation:
The definition for power (W) is the rate of energy (J) per unit of time (seconds). In this case the power output is 2kW, or 2000W. This means the energy rate of the engine must be 2000 joules per second, or 2kJ per second.
Refer to the diagram shown below.
h = original height of the pelican when the fish is dropped (not relevant).
S = distance traveled by the fish as a function of time, measured upward.
u = 0.5 m/s, the upward velocity with which the fish is dropped.
g = 9.8 m/s², the acceleration due to gravity.
Use the following equation:
S = ut + (1/2)gt²
S = (0.5 m/s)*(2.5 s) + 0.5*(-9.8 m/s²)*(2.5 s)²
= -29.375 m
The negative sign means that the fish drops by 29.375 m from the original height of h.
Answer: The fish is 29.375 m below where the pelican dropped it after 2.5 s.