150x1000 (turn km into m)
=150000m
150000 / 60 (hour to min)
=2500m/min
2500 / 60 (min to sec)
=41.6666666
=41,1/3 m/s
Cuts, sneeze, vomit, spit, cry
Answer:
640.59 g of NaCl.
Explanation:
Using Boiling point elevation,
ΔTb = kb * i * b
Where,
b = molality
kb = 0.52 °C kg/mole
i = van't koff factor
ΔTb = ΔTsol - ΔTsolv
= 2°C
2 = 0.52 * b
= 3.846 mol/kg.
Mass of water, solvent = 2.85 kg
Molality is the ratio of the number of moles of the solute to the mass of the solvent.
= 3.846 * 2.85
= 10.96 mol.
Mass of NaCl = molar mass * number of moles
= 58.44 * 10.96
= 640.59 g of NaCl.
Answer:
When she stretches her arms out,<em> B) her angular speed ω increases due to her moment of inertia decreasing</em>
Explanation:
The angular momentum of a rotating object is defined as the product of its moment of inertia and angular speed.
<em>L = I ω</em>
<em>where</em>
- <em>L is the angular momentum</em>
- <em>I is the moment of inertia</em>
- <em>ω is the angular speed</em>
<em />
According to the principle of conservation of angular momentum, if there is no external torque, angular momentum of the skater must remain conserved. If the initial and final moment of inertia is <em>I_i and I_f </em>while corresponding angular velocities are <em>ω_i and ω_f , </em>then the principle of conservation of angular momentum can be expressed as the following equation:
<em>(I_f) (ω_f) = (I_i) (ω_i)</em>
<em>ω_f / ω_i = I_i / I_f</em>
<em />
From the expression above, we can see that if the moment of inertia decreases, angular velocity would increase to conserve angular momentum of the skater.
Therefore, When she stretches her arms out,<em> her angular speed ω increases due to her moment of inertia decreasing.</em>
