Correct one is b
Good luck
Answer:
Gravity provides a downward force, resulting in the diver going downward. They speed up like any falling object would, the pull of gravity is a dominant force. (There is a drag force – as a result of moving through the air.)
I cant really say but i believe it is called extinction
Answer:
1027 N/C
3.42 x 10⁻⁶ T
Explanation:
I = Intensity of electromagnetic field = 1400 W/m²
E₀ = Maximum value of electric field
Intensity of electromagnetic field is given as
I = (0.5) ε₀ E₀² c
1400 = (0.5) (8.85 x 10⁻¹²) (3 x 10⁸) E₀²
E₀ = 1027 N/C
B₀ = maximum value of magnetic field
using the equation
E₀ = B₀ c
1027 = B₀ (3 x 10⁸)
B₀ = 3.42 x 10⁻⁶ T
Answer:
(a) Magnitude of static friction force is 109 N
(b) Minimum possible value of static friction is 0.356
Solution:
As per the question;
Horizontal force exerted by the girl, F = 109 N
Mass of the crate, m = 31.2 kg
Now,
(a) To calculate the magnitude of static friction force:
Since, the crate is at rest, the forces on the crate are balanced and thus the horizontal force is equal to the frictional force, f:
F = f = 109 N
(b) The maximum possible force of friction between the floor and the crate is given by:
![f_{m} = \mu_{s}N](https://tex.z-dn.net/?f=f_%7Bm%7D%20%3D%20%5Cmu_%7Bs%7DN)
where
N = Normal reaction = mg
Thus
![f_{m} = \mu_{s}mg](https://tex.z-dn.net/?f=f_%7Bm%7D%20%3D%20%5Cmu_%7Bs%7Dmg)
For the crate to remain at rest, The force exerted on the crate must be less than or equal to the maximum force of friction.
![f\leq f_{m}](https://tex.z-dn.net/?f=f%5Cleq%20f_%7Bm%7D)
![f \leq \mu_{s}mg](https://tex.z-dn.net/?f=f%20%5Cleq%20%5Cmu_%7Bs%7Dmg)
![109 \leq \mu_{s}\times 31.2\times 9.8](https://tex.z-dn.net/?f=109%20%5Cleq%20%5Cmu_%7Bs%7D%5Ctimes%2031.2%5Ctimes%209.8)
![\mu_{s}\geq 0.356](https://tex.z-dn.net/?f=%5Cmu_%7Bs%7D%5Cgeq%200.356)