What is the correct calculation for voltage if the resistance is 3 ohms and the current is 4 amps?

Ask Your Teacher A beam of light is incident from air on the surface of a liquid. If the angle of incidence is 33.5° and the ang

Oduvanchick [21]

Answer:

The critical angle for the liquid when surrounded by air is 30 degrees.

Explanation:

Given that,

The angle of incidence is 33.5° and the angle of refraction is 19.3°. Firstly, we can find the refractive index of the liquid. It can be calculated using Snell's law as :

$n=\dfrac{\sin i}{\sin r}\\\\n=\dfrac{\sin (33.5)}{\sin (19.3)}\\\\n=2$

The critical angle is given by :

$\theta_c=\sin^{-1}(\dfrac{n_1}{n_2})$

Here, $n_1$ is refractive index of air and $n_2$ is refractive index of liquid.

$\theta_c=\sin^{-1}(\dfrac{1}{2})\\\\\theta_c=30^{\circ}$

So, the critical angle for the liquid when surrounded by air is 30 degrees.

5 0

4 years ago

Jack and Jill are maneuvering a 3300 kg boat near a dock. Initially the boat's position is < 2, 0, 3 > m and its speed is

Paraphin [41]

Answer:

The workdone by Jack is $W_{jack} = -1050J$

The workdone by Jill is $W_{Jill} = 0J$

The final velocity is $v = 1.36 m/s$

Explanation:

From the question we are given that

The mass of the boat is $m_b = 3300kg$

The initial position of the boat is $P_i = (2 \r i + 0 \r j + 3\r k)m$

The Final position of the boat is $P_f = (4\r i + 0 \r j + 2\r k )\ m$

The Force exerted by Jack $\r F = (-420\r i + 0 \r j + 210\r k) \ N$

The Force exerted by Jill $\r F_{Jill} =(180 \r i + 0\r j + 360\r k)$

Now to obtain the displacement made we are to subtract the final position from the initial position

$\r P = P_f - P_i$

$= (4\r i + 0\r j + 2 \r k) - (2\r i + 0\r j + 3\r k )$

$= (2\r i + 0\r j -\r k )m$

Now that we have obtained the displacement we can obtain the Workdone

which is mathematically represented as

$W =\r F * \r P$

The amount of workdone by jack would be

$W_{jack} =\r F * \r P$

$= [(-420\r i +0\r j +210\r k)(2\r i + 0\r j - \r k)]$

$= (-420) (2) + (210)(-1)$

$= -840 - 210$

$=-1050J$

The amount of workdone by Jill would be

$W_{Jill} =\r F * \r P$

$= [(180 \r i + 0\r j + 360\r k)(2\r i +0\r j -\r k)]$

$= (180 )(2) +(360)(-1)$

$=0J$

According to work energy theorem the Workdone is equal to the kinetic energy of the boat

$W = K.E = \frac{1}{2} m *[v^2 - (1.1)^2]$

$-1050 = 0.5*3300 [*v^2- (1.1)^2]$

$-1050 = 1650 [v^2 -1.21]$

$0.6363 = v^2 -1.21$

$v^2 = 0.6363+1.21$

$v^2 =1.846$

$v = 1.36\ m/s$

6 0

4 years ago

WILL UPVOTE!!!Physics help please!!

liubo4ka [24]

Speed v = initial speed u + acceleration a x time t
v=u+at = 2 + 4*3 = 14 m/s

8 0

3 years ago

Why did you need a permanent magnet? What do you think would happen if you increased the

inysia [295]

Permanent magnets are important for their industrial uses especially when it comes to power generation and electric motors. The induction process for turbines and generators needs permanent magnets to turn mechanical motion into energy.

Exposing magnetized magnets to opposing external fields produces a demagnetizing effect. This effect is most apparent in permanent magnet materials having a non-linear demagnetization curve, such as Alnico. ... Other factors such as SHOCK and VIBRATION have very little effect on today's permanent magnet materials.

7 0

3 years ago

Some unpolarized light has an intensity of 1375 W/m2 before passing through three polarizing filters. The transmission axis of t

chubhunter [2.5K]

Answer:

intensity of the light that emerges from the three filters is 560.80 W/m²

Explanation:

Given data

intensity I = 1375 W/m2

angle 1 = 31.0°

angle 2 = 41.0°

to find out

intensity of the light that emerges from the three filters

solution

we know intensity of light pass 1st polarize = I/2 = 1375 / 2 = 687.5 W/m2

so intensity after 2nd polarize pass = I 1st cos²(θ)

I 2nd = 687.5 cos²(31) = 687.5 ( 0.836754) = 575.27 W/m2

and

intensity after 3rd polarize pass = I 2nd cos²(θ)

I 3rd = 575.27 cos²(41) = 575.27 (0.974839) = 560.80 W/m2

so that intensity of the light that emerges from the three filters is 560.80 W/m²

4 0

4 years ago