Answer:
(a) 
(b) 
(c) 
Explanation:
Given that,
(a) An electron accelerated from rest through a potential difference of 100 V. The De Broglie wavelength in terms of potential difference is given by :
Where
m and e are the mass of and charge on an electron
On solving,
V = 100 V
(b) V = 1 kV = 1000 V
(c) If 
Hence, this is the required solution.
Answer:
32 m/s
Explanation:
The speed of a bus is 30 m/s due East wrt the passenger
He also sees a passenger on the bus walking to the back at 2 m/s.
We need to find the passenger's velocity relative to the bus. As the observer sees that the bus and the passenger are moving in opposite direction. Let v is the relative velocity. So,
v = 30 m/s + 2 m/s
v = 32 m/s
Hence, the passenger's velocity relative to the bus is 32 m/s.
Answer:
Multiply the wavelength by the frequency.
Explanation:
The velocity of a wave is the frequency times the wavelength.
The formular for determinatio of mass number is this:
Mass number = number of proton + number of neutron
From the question, we are told that:
Mass number = 39
Proton number = 19
Number of proton = ?
Number of neutron = mass number - number of proton
Number of neutron= 39 - 19 = 20
Therefore, number of neurtron = 20.
