Answer:
a. cosθ b. E.A
Explanation:
a.The electric flux, Φ passing through a given area is directly proportional to the number of electric field , E, the area it passes through A and the cosine of the angle between E and A. So, if we have a surface, S of surface area A and an area vector dA normal to the surface S and electric field lines of field strength E passing through it, the component of the electric field in the direction of the area vector produces the electric flux through the area. If θ the angle between the electric field E and the area vector dA is zero ,that is θ = 0, the flux through the area is maximum. If θ = 90 (perpendicular) the flux is zero. If θ = 180 the flux is negative. Also, as A or E increase or decrease, the electric flux increases or decreases respectively. From our trigonometric functions, we know that 0 ≤ cos θ ≤ 1 for 90 ≤ θ ≤ 0 and -1 ≤ cos θ ≤ 0 for 180 ≤ θ ≤ 90. Since these satisfy the limiting conditions for the values of our electric flux, then cos θ is the required trigonometric function. In the attachment, there is a graph which shows the relationship between electric flux and the angle between the electric field lines and the area. It is a cosine function
b. From above, we have established that our electric flux, Ф = EAcosθ. Since this is the expression for the dot product of two vectors E and A where E is the number of electric field lines passing through the surface and A is the area of the surface and θ the angle between them, we write the electric flux as Ф = E.A
Given that,
Initial velocity , Vi = 0
Final velocity , Vf = 40 m/s
Acceleration due to gravity , a = 9.81 m/s²
Distance can be calculated as,
2as = Vf² - Vi²
2 * 9.81 *s = 40² - 0²
s = 81.55 m
For half height, that is, s = 40.77m
Vf= ??
2as = Vf² - Vi²
2 * 9.81 * 40.77 = Vf² - 0²
Vf² = 800
Vf = 28.28 m/s
Therefore, speed of roller coaster when height is half of its starting point will be 28 m/s.
Answer:
4.384 * 10^13
Explanation:
Given the expression :
[(6.67 * 10^-11) * (1.99 * 10^30)] ÷ [(1.74*10^3)*(1.74*10^3)]
Applying the laws of indices
[(6.67 * 1.99) *10^(-11 + 30)] ÷ [(1.74 * 1.74) * 10^3+3]
13.2733 * 10^19 ÷ 3.0276 * 10^6
(13.2733 / 3.0276) * 10^(19 - 6)
4.3840996 * 10^13
= 4.384 * 10^13
Answer:
Explanation:
When the box is on the ramp , component of its weight along the ramp
= mg sinθ
Friction force acting on it in upward direction
=μ mg cosθ
For sliding
μ mg cosθ < mg sinθ
μ cosθ < sinθ
.5 x cos35 < sin35
.41 < .57
So the box will slide
When sliding starts , kinetic friction acts
Net force in downward direction
mgsinθ - μ mg cosθ
acceleration
= gsinθ - μ g cosθ
= 5.62 - .3 x 9.8 x cos35
= 5.62 - 2.4
= 3.22 m /s²
This depends on whether the pipe is closed or open ended.
The fundamental frequency of a pipe is the simplest, smallest portion of a wave that can fit into a pipe. At the open end of a pipe, there is always an antinode - an area with maximum air movement.
If it is an open ended pipe, there is an antinode at each end, meaning that the length of the pipe is equal to 1/2 <span>λ
</span>. Manipulating the formula <span><span>v=fλ</span>
</span> to solve for the fundamental frequency leaves us with <span><span>f=<span>v/<span>2L</span></span></span>
</span> in an open ended pipe.
