Answer:
22km/h
Explanation:
The speed of the keys relative to the ground will be given by the sum of speed of keys with respect to the ground and the speed of keys with respect to the skater
Given that the speed of keys with respect to the ground is 8 m/s while the speed of keys with respect to skater is 14 km/h then the relative speed which combines both speeds will be 8+14=22 km/hr
From the planks equation
E=hv
V= c/ wave length
V= 3×10^8/30×10^-9
=1×10^16
E= hv
6.63×10^-34×1×10^16
= 6.63×10^-18
Answer:
electrons
Explanation:
electrons are negatively charged particles in an atom
The boiling point of ethanol is at 78.37°C. So, the energy must include sensible heat to raise 19°C to the boiling point and latent heat to change liquid to gas. The equation would be
Energy = Sensible heat + Latent heat
Energy = mCpΔT + mΔH
For ethanol,
Cp = 46.068 + 102,460T - 139.63T² - 0.030341T³ + 0.0020386T⁴ J/kmol·K
ΔH = 38,560 J/mol
Integrate the Cp expression to determine CpΔT:
CpΔT = ∫₂₉₂³⁵²(46.068 + 102,460T - 139.63T² - 0.030341T³ + 0.0020386T⁴ )dT
The upper limit is (78.37+273) = 352 K, while the lower limit is (19 + 273) = 292.
CpΔT = 2384857192 J/kmol·K
2,000 J = m(2384857192 J/kmol)(1 kmol/1000 mol) + m(38,560 J/mol)
m = 8.253×10⁻⁴ moles of ethanol
Since the molar mass of ethanol is 46.07 g/mol,
Mass = (8.253×10⁻⁴ mol)(46.07 g/mol)
Mass = 0.038 g ethanol
Two copper spheres are currently 1.2 meters apart. One sphere has a charge of +2.2•10-4 C and the other has a charge of -8.9•10-4 C, then the the force between the charged spheres is the force attractive.
<h3>What is Coulomb's law?</h3>
Coulomb's law can be expressed as that the electrical force between two charged bodies is directly proportional to the product of the quantity of charge on the bodies and inversely proportional to the square of the separation distance between the two bodies.
As given in the problem two copper spheres are currently 1.2 meters apart.One sphere has a charge of +2.2•10-4 C and the other has a charge of - 8.9•10-4 C.
As per coulomb's law, opposite charges attract each other.
Thus, If one sphere has a charge of +2.2•10-4 C and the other has a charge of -8.9•10-4 C, then the the force between the charged spheres is the force attractive.
Learn more about Coulomb's law here ;
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