The sentences are invalid and unsound.
<h3><u>Explanation</u>:</h3>
The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.
Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound.
Answer:
L = 2.8 cm
Explanation:
Period T = 4 / 12 = 1/3 s
T = 2π√(L/g)
L = (T/2π)²g
L = ((1/3)/2π)²9.8 = 0.02758... ≈ 2.8 cm
Explanation:
formula: <u>Mass</u>
Density x volume
2a) m=10kg v=0.3m³
10÷0.3=33.3 kg/m
2b) m = 160 kg V=0.1m³
160÷0.1=1600 kg/m
2c) m = 220 kg V = 0.02m³
220÷0.02=11000 kg/m
A wooden post has a volume of 0.025m³ and a mass of 20kg. Calculate its density in kg/m.
density = volume ÷ mass
20÷ 0.025=800 kg/m
Challenge: A rectangular concrete slab is 0.80m long, 0.60 m wide and 0.04m thick. Calculate its volume in m³.
Formula : Length x width x height = Volume
0.80 x 0.60 x 0.04 = 0.0192m³
B) The mass of the concrete slab is 180 kg. Calculate its density in kg/m.
density = volume ÷ mass
180 ÷ 0.0192 = 9375 kg/m
KE = ½mv² = ½(4.00 kg)(16.0 m/s)² = 512 J
