Answer:
the magnetic field experienced by the electron is 0.0511 T
Explanation:
Given the data in the question;
Wavelength λ = 21 cm = 0.21 m
we know that Bohr magneton μ
is 9.27 × 10⁻²⁴ J/T
Plank's constant h is 6.626 × 10⁻³⁴ J.s
speed of light c = 3 × 10⁸ m/s
protein spin causes magnetic field in hydrogen atom.
so
Initial potential energy = -μ
B × cos0°
= -μ
B × 1
= -μ
B
Final potential energy = -μ
B × cos180°
= -μ
B × -1
= μ
B
so change in energy will be;
ΔE = μ
B - ( -μ
B )
ΔE = 2μ
B
now, difference in energy levels will be;
ΔE = hc/λ
2μ
B = hc/λ
2μ
Bλ = hc
B = hc / 2μ
λ
so we substitute
B = [(6.626 × 10⁻³⁴) × (3 × 10⁸)] / [2(9.27 × 10⁻²⁴) × 0.21 ]
B = [ 1.9878 × 10⁻²⁵ ] / [ 3.8934 × 10⁻²⁴ ]
B = 510556326.09
B = 0.0511 T
Therefore, the magnetic field experienced by the electron is 0.0511 T
Answer:
The car strikes the tree with a final speed of 4.165 m/s
The acceleration need to be of -5.19 m/seg2 to avoid collision by 0.5m
Explanation:
First we need to calculate the initial speed 
Once we have the initial speed, we can isolate the final speed from following equation:
Then we can calculate the aceleration where the car stops 0.5 m before striking the tree.
To do that, we replace 62 m in the first formula, as follows:

Answer:
Total time taken=110 seconds
Total distance traveled=480m
Explanation:
First of all, we find the total time taken:
For that, we use the formula : Distance/Speed= Time
Time for part 1 : 200/5=40 seconds
Time for part 2 : 280/4=70seconds
Total time taken=110 seconds
Total distance traveled=480m
Average Speed= 480/110=4.36 m/s
Total displacement=200-280=-80m (Since this is displacement, we need to find the distance between the initial and final point. Also, I've taken east direction as positive and west as negative)
Average Velocity=-80/110=-0.72 m/s
OR 0.72m/s towards west.
Velocity because it gives the displacement and time