a system absorb 500 J of heat and the same time 400J of work is done one the system find change in internal enery​ ?

+ 900 J

Explanation:

Since the total energy change ΔE = internal energy change ΔU since there is no change in kinetic and potential energy,

ΔE = ΔU

ΔE = Q - W where Q = heat absorbed by system and W = work done by system

Now since the system absorbs 500 J of heat, Q = + 500 J and work of 400 J is done on the system, W = -400 J

So,  the values of the variables into the equation, we have

ΔE = Q - W

ΔE = + 500 J - (-400 J)

ΔE = + 500 J + 400 J  

ΔE = + 900 J

So, the internal energy change, ΔE = + 900 J

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =