Answer:
1.11 m/s
Explanation:
The motion of the boat is an example of accelerated motion, since the velocity is not constant. However, we don't need to find the acceleration, because we are only interested in the average velocity of the boat, which is given by:

where d is the total distance covered and t the time taken. In this problem, the boat covered a distance of d = 20 m and it takes t = 18 s, therefore the average velocity is

Answer:
The entropy change of the sample of water = 6.059 x 10³ J/K.mol
Explanation:
Entropy: Entropy can be defined as the measure of the degree of disorder or randomness of a substance. The S.I unit of Entropy is J/K.mol
Mathematically, entropy is expressed as
ΔS = ΔH/T....................... Equation 1
Where ΔH = heat absorbed or evolved, T = absolute temperature.
<em>Given: If 1 mole of water = 0.0018 kg,</em>
<em>ΔH = latent heat × mass = 2.26 x 10⁶ × 1 = 2.26x 10⁶ J.</em>
<em>T = 100 °C = (100+273) K = 373 K.</em>
<em>Substituting these values into equation 1,</em>
<em>ΔS =2.26x 10⁶/373</em>
ΔS = 6.059 x 10³ J/K.mol
Therefore the entropy change of the sample of water = 6.059 x 10³ J/K.mol
Nitrogen fixing bacteria changes dead plants and animals into ammonia compounds.
<h2>What is nitrogen fixation?</h2>
Atmospheric nitrogen is converted into nitrogen oxides by the action of lightning, which helps its incorporation into the soil.
<h3>Characteristics of Nitrogen fixing bacteria</h3>
- Nitrogen is fixed by these bacteria and other prokaryotes through various metabolic processes, which convert it into different usable compounds, such as ammonia (NH3) and ammonium ion (NH4+).
- These microorganisms can be found in soil and water, or as plant symbionts.
Therefore, we can conclude that nitrogen fixing bacteria fix nitrogen from the air, that is, they originate soluble compounds by plants, such as ammonia.
Learn more about nitrogen fixation here: brainly.com/question/14726009
Boy X and Boy Y both move backward in opposite directions.
Answer:
-0.01 mm
Explanation:
We are given that
The value of one division of vernier scale =0.5 mm
The value of one main scale division=0.49 mm
We have to find the value of least count of the instrument in mm.
We know that
Leas count of vernier caliper=1 main scale division-1 vernier scale division
Least count of vernier caliper=0.49-0.50=-0.01 mm
Hence, the least count of the instrument=-0.01 mm
Answer: -0.01 mm