Answer:
U = - 4 x 
Explanation:
ΔV = potential difference = 
Volts
q = charge on electron = 
C
electric potential energy is given as
U = q ΔV = ( ) ( )
= - 4 x
D = 1/2 x g × t²
145 = 1/2 × 9.8 × t²
t = 5.4 s
Answer : The velocity of an electron is, 
Explanation :
According to de-Broglie, the expression for wavelength is,
and,
where,
p = momentum, m = mass, v = velocity
So, the formula will be:
.............(1)
where,
h = Planck's constant = 
= wavelength = 
m = mass of electron = 
v = velocity of electron = ?
Now put all the given values in formula 1, we get:
Thus, the velocity of an electron is,
Answer:
1000m3
Explanation:
12000=mass*gravity, considerinh gravity 10
12000=mass*10 then mass=1200Kg
With density 1.2Kg/m3
1.2Kg ... 1m3
1200Kg ... 1000m3
End
Answer:
This is because below 4°c, water unlike other materials becomes less dense when it's temperature is further lowered.
Explanation:
Due to the unusual nature of water; at about 4°c, the behavior of the density of water in relation to its temperature reverses. This means that water becomes less dense as it becomes colder below 4°c. The colder parts therefore floats to the top of the water body while the warmer part sinks allowing the top to freeze and the remaining body below to remain in its liquid state.
The freezing of the top of the lake alone protects the remaining depth of water from freezing by acting as an insulator and preventing further heat loss from the water to the ambient space. If this had not been the case, and water froze all through, marine lives will freeze to death and it will be more difficult to melt the ice come the next summer.
This behavior is due to the hydrogen bonding of the water molecules.
