Answer:

Explanation:
Let assume that 100 kg of the compound is tested. The quantity of kilomoles for each element are, respectively:




Ratio of kilomoles oxygen to kilomole nitrogen is:


It means that exists 1.499 kilomole oxygen for each kilomole nitrogen.
The empirical formula for the compound is:

-- The table tennis ball bounces back with virtually its entire original speed.
-- The bowling ball rolls forward, so slowly that only complex expensive laboratory equipment can detect and measure its speed.
-- Once again, momentum is conserved !
Answer:
Explanation:
Given
mass of book(m)=2.1 kg
height up to which book is lifted is (h)2.2 m
height of person 
Potential energy of book relative to ground=mgh

(b)PE w.r.t to person head =mg(h-h0)

work done by person in lifting box 2.2 m w.r.t floor
Word done =Potential Energy of box relative to floor=45.2 J
Answer:
3.7kg
Explanation:
The following data were obtained from the question:
Volume = 3.7L
Mass =?
Next, we shall convert 3.7L to m³.
This is illustrated below:
1000L = 1m³
Therefore, 3.7L = 3.7/1000 = 0.0037m³
Now, we can obtain the mass of the water as shown below:
Density of water = 1000kg/m³
Volume of water = 0.0037m³
Mass of water =..?
Density = Mass /volume
1000kg/m³ = Mass /0.0037m³
Cross multiply
Mass = 1000Kg/m³ × 0.0037m³
Mass = 3.7Kg
Therefore, the mass of the water is 3.7Kg.