1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Svetlanka [38]
2 years ago
9

Exercises

Physics
1 answer:
Crank2 years ago
5 0

\\ \rm\Rrightarrow \dfrac{1}{u}+\dfrac{1}{v}=\dfrac{1}{f}

\\ \rm\Rrightarrow \dfrac{1}{u}=\dfrac{1}{-10}+\dfrac{1}{38}

\\ \rm\Rrightarrow \dfrac{1}{u}=\dfrac{-19+5}{190}

\\ \rm\Rrightarrow \dfrac{1}{u}=\dfrac{-14}{190}

\\ \rm\Rrightarrow u=\dfrac{190}{-14}

\\ \rm\Rrightarrow u=13.6cm

Real

You might be interested in
The electric field of a sinusoidal electromagnetic wave obeys the equation E=(375V/m)cos[(1.99×107rad/m)x+(5.97×1015rad/s)t].a.
andrey2020 [161]

Answer:

A) max = Eo = 375 V/m, B)  B = 125 10⁻⁸ T , C) f = 9.50 101⁴ Hz, D) λ = 3.158 10⁻⁷ m, E)  T = 1.05 10⁻¹⁵ s , F) invisible for humans   G)  v = c = 3 10⁸ m/s

Explanation:

The expression given for the electric field is

       E = 375 cos (1.99 107x + 5.97 105t)

The general formula for the electric field of a transverse traveler is

     E = Eo cos (kx-wt)

Where k is the wave number and w the angular velocity

A) The amplitudes as electric is

     Emax = Eo = 375 V / m

B) the electric and magnetic field are related

     E / B = c

     B = E / c

     B = 375/3 108

     B = 125 10⁻⁸ T

C) angular velocity and frequency is related

    .w = 2π f

     f = w / 2π

     f = 5.97 10¹⁵ / 2π

     f = 9.50 101⁴ Hz

D) the speed of light has the formula

      c = λ f

      λ = c / f

      λ = 3 10⁸ / 9.50 10¹⁴

      λ = 3.158 10⁻⁷ m

E) The period

     T = 1 / f

     T = 1 / 9.5 10¹⁴

     T = 1.05 10⁻¹⁵ s

F) let's reduce the wavelength nm

   λ = 3.158 10⁻⁷ m (10⁹nm / 1m)

   λ = 3.158 10²nm = 315.3 nm

The visible radiation range is between 400nm and 700nm. This radiation is ultraviolet and is invisible humans

G) All electromagnetic radiation has a speed at the speed of light (c)

      v = c = 3 10⁸ m/s

5 0
3 years ago
A brick is resting on a smooth wooden board that is at a 30° angle. What is one way to overcome the static friction that is hold
nata0808 [166]

Answer:

We apply force to move the brick.

Explanation:

Let me first of define a force .

A force is something applied to an object or thing to change it's internal or external state.

Now if a brick is resting on smooth wood inclined at 30° to the horizontal for us to overcome the friction which is also a force we have to apply a force greater than the gravity force acting on the body and then depending on the direction of the applied force the angle to apply it also.

3 0
3 years ago
The speed limmit on an interstate highway is posted at 75mi/h. What is the speed in kilometers per hour? In feet per second?
jok3333 [9.3K]

I uploaded the answer to a file hosting. Here's link:

tinyurl.com/wpazsebu

4 0
2 years ago
a 5 charge is locataed 1.25 m to the left of a -3 charge. What is the magnitude and direction of the electrostatic force on the
Alika [10]

Answer:

The force is 86.5×10^9 N towards the negative charge (to the right)

Explanation:

The electrostatic force on the charges is given by Coulomb's law;

F= Kq1q2/r^2

This an inverse square law.

F= electrostatic force on the charges

K= constant of Coulomb's law

q1 and q2= magnitude of the charges

Since K= 9.0×10^9Nm^2C^2

F= 9.0×10^9 × 5 × 3/(1.25)^2 = 135×10^9/1.56

F= 86.5×10^9 N

The force is 86.5×10^9 N towards the negative charge.

5 0
2 years ago
An explorer is caught in a whiteout (in which the snowfall is so thick that the ground cannot be distinguished from the sky) whi
alexdok [17]

Actual displacement that he required to move

d_1 = 5.4 km towards North

Displacement that he moved due to snow is

d_2 = 8.1 km at 47 degree North of East

now in vector component form we can say

d_1 = 5.4 \hat j

d_2 = 8.1 cos47 \hat i + 8.1 sin47 \hat j

d_2 = 5.52 \hat i + 5.92 \hat j

now the displacement that is more required to reach the destination is given as

d = d_1 - d_2

d = 5.4\hat j - (5.52 \hat i + 5.92\hat j)

d = -5.52 \hat i - 0.52 \hat j

so the magnitude of the displacement is given as

d = \sqrt{5.52^2 + 0.52^2}

d = 5.54 km

its direction is given as

\theta = tan^{-1}\frac{0.52}{5.52} = 5.38 degree

so it is 5.54 km towards 5.38 degree North of West.

4 0
3 years ago
Other questions:
  • 2. A liquid that is twice as dense as water is used in a barometer. With this barometer, atmospheric pressure would push the liq
    13·1 answer
  • A 1250 kg car is stopped at a traffic light. A 3550 kg truck moving at 8.33 m/s hits the car from behind. If bumpers lock, how f
    8·1 answer
  • Which theory was first proposed by Albert Einstein
    14·2 answers
  • A standard for comparison that helps to ensure that the experimental result is caused by the condition being tested is the ____.
    6·1 answer
  • A student has an 80 g sample of a radioactive material that has a half-life of 20 seconds. How much material will he have left a
    5·1 answer
  • I WILL MARK YOU TOP IF YOU HELP ME I NEED THIS ASAP!!!!
    9·1 answer
  • explain how a roller coaster functions using gravity and momentum. Why does it not need an engine or a motor to speed it up and
    9·2 answers
  • At which latitude would tropical rain forests be most likely?
    15·1 answer
  • A hiker yells out "Hello!" into a canyon. If the echo of their voice
    7·1 answer
  • Of all the hydrogen in the oceans, 0.0300 % of the mass is deuterium. The oceans have a volume of 317 million mi³.(a) If nuclear
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!