Answer: The right Answer is Velocity has both speed and direction.
Explanation:
i took the test
Answer:
i)20369 photons
ii) 40 ps
Explanation:
Momentum of one Sodium atom:

In other to stop it, it must absorb the same momentum in photons:

Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:

Work can be defined as the energy transferred from a body to its sorroundings, the energy spent to move a body, or the energy you need to alter a charged particle, so no energy, no work; thus, the statement is true.
Explanation:
Given that,
Initial speed of the car, u = 88 km/h = 24.44 m/s
Reaction time, t = 2 s
Distance covered during this time, 
(a) Acceleration, 
We need to find the stopping distance, v = 0. It can be calculated using the third equation of motion as :


s = 74.66 meters
s = 74.66 + 48.88 = 123.54 meters
(b) Acceleration, 


s = 37.33 meters
s = 37.33 + 48.88 = 86.21 meters
Hence, this is the required solution.
Answer:
221.17 kJ
Explanation: Note the heat of vaporization is in kJ/mol,then to determine the number of moles of water: divide the mass by 18. Then multiply the number of moles by the molar heat of vaporization of water.
N = 97.6 ÷ 18
Q=molar heat *moles
Q = (40.79) * (97.6 ÷ 18)
This is approximately 221.17 kJ