De broglie wavelength, 
, where h is the Planck's constant, m is the mass and v is the velocity.
Mass of hydrogen atom, 
v = 440 m/s
Substituting
Wavelength 
So the de broglie wavelength (in picometers) of a hydrogen atom traveling at 440 m/s is 902 pm
Answer:
It is easier to scale the voltage of AC from high to low and low to high than with DC
Explanation:
typically power is used far away from the place where it's generated so to ensure that transmission losses( copper losses) are minimized voltage has to be stepped up during transmission..but due to the fact that most house hold equipment requires low voltage levels it has to be stepped down once it reaches a household/ domestic load...it's easier to do this for Ac than for DC.
Answer:
1.11 V
Explanation:
Given that the Einstein photoelectric equation states that;
KE = E - Wo
E = energy of incident photon
Wo= work function of the metal
E = hf = 6.64 x 10-34 * 6 x 1014
E = 39.84 * 10^-20 J or 3.98 * 10^-19 J
KE = 3.98 * 10^-19 J - 2.2 x 10-19J
KE = 1.78 * 10^-19J
We convert this value of KE to electron volts
KE = 1.78 * 10^-19J/1.6 x 10-19C
KE = 1.11 eV
Hence; 1.11 V will be just sufficient to stop electrons emitted by the sodium photo-plate reaching the collector plate.
Answer:
Energy due to air resistance = 31.8 Joules
Explanation:
According to the law of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another
Kinetic Energy + Energy due to air resistance = Potential energy..........(1)
If there is no energy loss due to air resistance, potential energy = kinetic energy
mass, m = 1.5 kg
height, h = 4.0 m
speed, v = 6 m/s
Kinetic energy = 0.5 mv²
Kinetic energy = 0.5 * 1.5 * 6²
Kinetic energy = 27 Joules
Potential Energy = mgh
Potential energy = 1.5 * 9.8 * 4
Potential energy = 58.8 Joules
From equation (1)
27 + Energy due to air resistance = 58.8
Energy due to air resistance = 58.8 - 27
Energy due to air resistance = 31.8 Joules
Answer:
Action force and Reaction force
Explanation:
The action force which is the balanced rock pushing down due to gravity and the reaction force pushing the equal amount of force. These two things are stated in Newtons third law, where he states that "Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first." Also, he states that "all forces acts in pairs," meaning that every force exerted, there is an opposite force on the first.
