Answer:
2.11 m
Explanation:
<u>Given data</u>
h=6.626×
(plank constant)
L=45.7 pm
n=n2-n1
n=5-1
n=4
<em>where,</em>
<em>n2=5</em>
<em>n1=1</em>
<u>To find:</u>
E=?
λ=? (Wavelength)
<u>solution</u>
The energy stored in an electron at a specified level is given by;
E=
×
÷8m
..........(1)
<em>m=mass of electron(9.1×</em>
)
<em>l=length of box</em>
<u>To find E</u>
putting the value of given data in eq(1)
E=9.41×
<u>To find λ</u>
λ=hc/E............................(2)
c=3×
(speed of light)
putting the value in eq 2 to find wavelength
λ=2.11 m
<u></u>
<u>Note:</u>
There is a chance in calculation error. but the method is correct to solve the problem.
The ideal gas law allows a scientist to calculate the number of moles that the other gas laws do not. The ideal gas law is given as
P V = n RT
rearranging the equation by dividing both side by "RT", we get
PV/(RT) = nRT/(RT)
n = PV/(RT)
inserting the values of pressure, volume and temperature, we get number of moles.
Answer:
25.6 V
Explanation:
The kinetic energy of electron associated with its potential difference is given by eV which is equal to the 1/2 mv^2.
m = 9.1 x 10^-31 kg, v = 3 x 10^6 m/s, e = 1.6 x 10^-19 C
eV = 1/2 m v^2
V = mv^2 / 2 e
V = (9.1 x 10^-31) x (3 x 10^6)^2 / (2 x 1.6 x 10^-19)
V = 25.6 V
That's false. It's the other way around. One light year is a distance that's a little farther than 63,000 astronomical units.
A mass suspended from a spring is oscillating up and down, (as stated but not indicated).
A). At some point during the oscillation the mass has zero velocity but its acceleration is non-zero (can be either positive or negative). <em>Yes. </em> This statement is true at the top and bottom ends of the motion.
B). At some point during the oscillation the mass has zero velocity and zero acceleration. No. If the mass is bouncing, this is never true. It only happens if the mass is hanging motionless on the spring.
C). At some point during the oscillation the mass has non-zero velocity (can be either positive or negative) but has zero acceleration. <em>Yes.</em> This is true as the bouncing mass passes through the "zero point" ... the point where the upward force of the stretched spring is equal to the weight of the mass. At that instant, the vertical forces on the mass are balanced, and the net vertical force is zero ... so there's no acceleration at that instant, because (as Newton informed us), A = F/m .
D). At all points during the oscillation the mass has non-zero velocity and has nonzero acceleration (either can be positive or negative). No. This can only happen if the mass is hanging lifeless from the spring. If it's bouncing, then It has zero velocity at the top and bottom extremes ... where acceleration is maximum ... and maximum velocity at the center of the swing ... where acceleration is zero.
