During takeoff, an airplane goes from 0 to 56 m/s in 9 s. How fast is it going after 4 s?

The charge on the square plates of a parallel-plate capacitor is Q. The potential across the plates is maintained with constant

jasenka [17]

Answer:

D) Q/2

Explanation:

The amount of charge on a capacitor is given by:

Q = CV

where

C is the capacitance

V is the voltage

The capacitance of a parallel-plate capacitor is given by

$C=\epsilon_0 \frac{A}{d}$

where

$\epsilon_0$ is the vacuum permittivity

A is the area of the plates

d is the separation between the plates

Substituting the last formula into the first one, we can write

$Q=\epsilon_0 \frac{AV}{d}$

In this problem, the two plates are pulled apart to twice their original separation, so

d' = 2d

While the voltage V is kept constant. Therefore, the new charge stored in the capacitor will be

$Q'=\epsilon_0 \frac{AV}{2d}=\frac{1}{2} \epsilon_0 \frac{AV}{d}=\frac{Q}{2}$

8 0

3 years ago

In your frame, a person is moving in the positive x-direction at a speed of 40,000 km / s. Suppose that a streetlamp located at

nexus9112 [7]

Answer:

proper time taken by the person is 9.911 × 10⁻⁵ s

Explanation:

speed of the person in x- direction = 40,000 km/s

= 40,000 × 10³ m/s

= 4 × 10⁷ m/s

when the person just passes the street lamp is switched on which is at x =4 km

Lorentz factor = $\gamma = \dfrac{1}{\sqrt{1-\dfrac{r^2}{c^2}}}$

= $\dfrac{1}{\sqrt{1-\dfrac{(4 \times 10^7)^2}{(3 \times 10^8)2}}}$

= 1.009

time taken in your frame of reference,t = $\dfrac{D}{v}$

= $\dfrac{4}{40000} = 10 ^{-4}s$

proper time = $t_0 = \dfrac{t}{\gamma}=\dfrac{10^{-4}}{1.009}= 9.911 \times 10^{-5} s$

hence, proper time taken by the person is 9.911 × 10⁻⁵ s

5 0

3 years ago

A double-slit arrangement produces bright interference fringes for sodium light ( λ = 603 nm) that are angularly separated by 0.

ohaa [14]

Answer:

θ for water = 0.3684°

Explanation:

given data

wavelength λ = 603 nm

angle θ = 0.49°

index of refraction n = 1.33

to find out

angular fringe separation

solution

we know that double slit interference is here

m λ = d sin(θ) .................1

so for air it will be

m λ(air) = d sin(θ)air ...........2

and for water it will be

m λ(water) = d sin(θ)water .............3

now we take here ratio of equation 2 and 3

$\frac{\lambda (water)}{\lambda(air)}$ = $\frac{sin(\Theta)water}{sin(\Theta)air}$

and

ratio of wavelength is = $\frac{1}{n}$

ratio of wavelength = $\frac{1}{1.33}$

ratio of wavelength = 0.75187

so

sin(θ)water = sin(θ)air (0.75187)

sin(θ)water = sin(0.49) (0.75187)

sin(θ)water = 0.006429

so (θ)water is

(θ)water = 0.3683°

we notice here that by using small angle formula

we have approximate sin(θ) = θ

so θ for water is = $\frac{\Theta }{n}$

θ for water = $\frac{0.49}{1.33}$

θ for water = 0.3684°

7 0

3 years ago

A horizontal board of length 6.1 m and mass 12.8 kg rests on two supports. The first support is at one end of the board. The sec

Svetllana [295]

Answer:102.84 N

Explanation:

Given

Mass of board $m=12.8\ kg$

Length of board $l=6.1\ m$

First support is at one end and second support is at a distance of 2.38 m from the other end

Suppose $R_1$ and $R_2$ are the reactions at the two support

Taking moment about the first end we can write

$mg\times \dfrac{6.1}{2}-R_2(6.1-2.38)=0$

$R_2=\dfrac{12.8\times 9.8 \times 3.05}{3.72}$

$R_2=102.84\ N$

5 0

3 years ago

You measure an angle of 21.1 when the light passes through a grating with 610 lines per mm. What is the wavelength of the light?

vesna_86 [32]

The wavelength is 590 nm.

<h3>Calculation:</h3>

The equation for diffraction is given as,

dsinθ = nλ

λ = dsinθ/n

Given,

θ = 21.1°

1/d = 1/610 lines per mm

n = 1

d = 1/610 lines per mm

= 1.639 × 10⁻⁶

Now, put the values in the equation

λ = dsinθ/n

λ = 1.639 × 10⁻⁶ × sin 21.1°/1

= 590 nm

Hence, the wavelength is 590 nm.

Learn more about diffraction here:

brainly.com/question/28166642

#SPJ4

5 0

2 years ago