Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Every living organism needs nutrients to build tissues and carry out essential life functions.
Answer:
the answers should be B and D
Answer:
Option B. 6.25 J/S
Explanation:
Data obtained from the question include:
t (time) = 2secs
F (force) = 50N
d (distance) = 0.25m
P (power) =?
The power can be obtained by using the formula P = workdone/time.
P = workdone / time
P = (50 x 0.25)/ 2
P = 6.25J/s
Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :

Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :
