Given :
Frequency ,
.
To Find :
The length of a half wavelength dipole .
Solution :
Now , wavelength is given by :

Now , half length is given by :

Therefore , length of a half wavelength dipole is 1.5 cm .
Hence , this is the required solution .
Answer:
I'm pretty sure this is not a complete question. My guess is that you are trying to add/subtract vectors. Vectors have both magnitude and direction, so vector A is pretty clear, but a magnitude of 13 (i'm guessing a resultant) without a direction is weird.
IF 13 is the magnitude of the resultant, vector B added to vector A could have any magnitude 17 ≤ B ≤ 43
It could have any direction of
θ = (225 - 180) ± arcsin(13/30)
θ = 45 ± 25.679...
70.679 ≤ θ ≤ 19.321
components of vector B would be
Bx = |B|cosθ
By = |B|sinθ
Answer:
3500N
Explanation:
Given parameters:
Mass of driver = 50kg
Speed = 35m/s
Time = 0.5s
Unknown:
Average force the seat belt exerts on her = ?
Solution:
The average force the seat belt exerts on her can be deduced from Newton's second law of motion.
F = mass x acceleration
So;
F = mass x 
F = 50 x
= 3500N
The answer to this question is a) sulfur