T<span>his is a straightforward question related to the surface energy of the droplet. </span>
<span>You know the surface area of a sphere is 4π r² and its volume is (4/3) π r³. </span>
<span>With a diameter of 1.4 mm you have an original droplet with a radius of 0.7 mm so the surface area is roughly 6.16 mm² (0.00000616 m²) and the volume is roughly 1.438 mm³. </span>
<span>The total surface energy of the original droplet is 0.00000616 * 72 ~ 0.00044 mJ </span>
<span>The five smaller droplets need to have the same volume as the original. Therefore </span>
<span>5 V = 1.438 mm³ so the volume of one of the smaller spheres is 1.438/5 = 0.287 mm³. </span>
<span>Since this smaller volume still has the volume (4/3) π r³ then r = cube_root(0.287/(4/3) π) = cube_root(4.39) = 0.4 mm. </span>
<span>Each of the smaller droplets has a surface area of 4π r² = 2 mm² or 0.0000002 m². </span>
<span>The surface energy of the 5 smaller droplets is then 5 * 0.000002 * 72.0 = 0.00072 mJ </span>
<span>From this radius the surface energy of all smaller droplets is 0.00072 and the difference in energy is 0.00072- 0.00044 mJ = 0.00028 mJ. </span>
<span>Therefore you need roughly 0.00028 mJ or 0.28 µJ of energy to change a spherical droplet of water of diameter 1.4 mm into 5 identical smaller droplets. </span>
Answer:
Answer: Chemical change; Chemical property of heat of combustion
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
Explanation:
Answer:
V2= 625 cm^3
Explanation:
P1 × V1 = P2 × V2
P1 (initial pressure)=125 kPa
V1 ( initial volume)= 450 cm^3
P2 (final pressure)=90kPa
V2 (final volume)= ?
Rearrange the equation to make V2 the subject, since it is the value we are trying to find
V2=(P1 × V1)/P2
V2= (125 ×450)/90
V2= 625 cm^3
Answer:
A one-point pH change indicates the strength of the acid or base has increased or decreased tenfold; a 2-point change indicates a 100-fold change in acidity or alkalinity, and a 3-point change in pH indicates a 1000-fold change. Examples: • An increase in pH from 7.0 to 8.0 means the water is 10 times more basic.
Explanation:
