Answer:
D
Explanation:
6CO² + 6H²O > sunlight, chlorophyll, enzymes > C⁶H¹²O⁶ + 6O²
The lungs hold air that is taken in. Oxygen gas noticeable all around moves into the blood. The heart pumps to transports this oxygenated blood to cells in the body that need it to deliver vitality.
We don't know anything about the amount of distance it travels, but that's okay. The only equation we need here is
velocity(final) = velocity(initial) + acceleration * time
vf = vi + (a * t)
The ball is dropped from rest, so vi = 0 m/s.
We want it so that the ball hits the ground with a final velocity of 60 m/s, so vf = 60 m/s.
We are given the acceleration due to gravity, a = 9.8 m/s^2.
We are solving for the time, t = ?.
Now we just plug in the values.
vf = vi + (a * t)
60 m/s = 0 m/s + (9.8 m/s^2)*(t)
60 = 9.8t
60 / 9.8 = t
t = 6.122 s
Hopefully this is the right answer.
Halflife is the time taken by a radioactive substance by half its original mass. In this case the half life of the substance is 3 hours.
Therefore; New mass = Original mass × (1/2)^n where n is the number of half lives. In this case, the half life is 3 hours and therefore; the number of half lives in 6 hours will be two.
= if the original mass is 100%
new mass = 100 × (1/2)^2
= 100 × 1/4 = 25%
The remaining mass will be 1/4 of the original mass, meaning a fraction of 3/4 of the initial mass will have decayed.
Thus; the answer is 3/4
