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
attashe74 [19]
3 years ago
8

You are on a train that is traveling at 3.0 m/s along a level straight track. Very near and parallel to the track is a wall that

slopes upward at a 12 angle with the horizontal. As you face the window (0.90 m high, 2.0 m wide) in your compartment, the train is moving to the left, as the drawing indicates. The top edge of the wall first appears at window corner A and eventually disappears at window corner B. How much time passes between appearance and disappearance of the upper edge of the wall
Physics
1 answer:
loris [4]3 years ago
5 0

Questions Diagram is attached below

Answer:

T=2.08s

Explanation:

From the question we are told that:

Speed of Train V=3.0m.s

Angle \theta=12\textdegree

Height of window h_w=0.90m

Width of window w_w=2.0m

The Horizontal distance between B and A from Trigonometric Laws is mathematically given by

 b=\frac{0.9}{tan12}

 b=4.23

Therefore

Distance from A-A

 d_a=2.0+4.23

 d_a=6.23

Therefore

Time Required to travel trough d is mathematically given as

 T=\frac{d_a}{v}

 T=\frac{6.23}{3}

 T=2.08s

You might be interested in
In this circuit (see picture), which resistor will draw the least power?
Basile [38]
A few different ways to do this: 

Way #1: 
The current in the series loop is  (12 V) / (total resistance) . 
(Turns out to be 2 Amperes, but the question isn't asking for that.)

In a series loop, the current is the same at every point, so it's
the same current through each resistor.

The power dissipated by a resistor is  (current)² · (resistance),
and the current is the same everywhere in the circuit, so the
smallest resistance will dissipate the least power.  That's  R1 .

And by the way, it's not "drawing" the most power.  It's dissipating it.

Way #2:
Another expression for the power dissipated by a resistance is

                 (voltage across the resistance)²  /  (resistance)  .

In a series loop, the voltage across each resistor is

          [ (individual resistance) / (total resistance ] x battery voltage.

So the power dissipated by each resistor is

         (individual resistance)² x [(battery voltage) / (total resistance)²]

This expression is smallest for the smallest individual resistance.
(The other two quantities are the same for each individual resistor.)
So again, the least power is dissipated by the smallest individual resistance.
That's R1 .                                      

Way #3:  (Einstein's way)
If we sat back and relaxed for a minute, stared at the ceiling, let our minds
wander, puffed gently on our pipe, and just daydreamed about this question
for a minute or two, we might have easily guessed at the answer.

===>  When you wire up a battery and a light bulb in series, the part
that dissipates power, and gets so hot that it radiates heat and light, is
the light bulb (some resistance), not the wire (very small resistance).
3 0
3 years ago
Rita places a 2.5 kg block on a frictionless inclined plane that is 30 degrees above horizontal. She applies a horizontal force,
vitfil [10]

Answer:

14.2

Explanation:

find horizontal force of the weight = 2.5kg x 9.8 Sin30 = 12.3 N

to prevent the sliding she needs to pull horizontally

Fh = 12.3 /Cos 30 =14.2N

7 0
3 years ago
The energy of the electron in Hydrogen atom can be shown to be given by En = -13.6/n^2 eV, where n represents the principal quan
Tpy6a [65]

Answer:

This represents radiation in ultra-violet region .

Explanation:

Energy of the orbit where n = 3 is given as follows

E_3 =- \frac{13.6 }{3^2}

E_3 =- \frac{13.6 }{9} = -1.511 eV

Energy of the orbit where n = 1 is given as follows

E_1 =- \frac{13.6 }{1^2}

E_1 =- \frac{13.6 }{1} = 13.6 eV

Difference of [tex]E_3 and [tex]E_1 = - 1.511+ 13.6

= 12.089 eV.

The wavelength of light having this energy in nm is given by the expression as follows

Wavelength in nm = 1244 / energy in eV

= 1244 / 12.089

= 102.90 nm

This represents radiation in ultra-violet region .

8 0
3 years ago
Katie and Mark sit next to one another in class. She has a mass of 40 kg and his mass is 65 kg.
OlgaM077 [116]
A :-) for this question , we should apply
F = GMm by d^2
( For making the calculation easy , first remove the decimals )
Given : G = 6.7 x 10^-11 Nm^2 / kg^2
= 67 x 10^-12 Nm^2 / Kg^2
M = 65 kg
m = 40 kg
d = 0.5 m
Solution -
F = GMm by d^2
F = 67 x 10^-12 x 65 x 40 by 0.5 x 0.5
F = 4355 x 40 x 10^-12 by 0.25
F = 174200 x 10^-12 by 0.25
F = 696800 x 10^-12

.:. The Gravitational force between mark and Katie is 696800 x 10^-12
6 0
3 years ago
As the phase angle is decreased, the power factor is
Darina [25.2K]
The answer is increased.  A power factor of one or "unity power factor" is the aim of any electric utility business from the time when if the power factor is less than one, they have to give more current to the user for an assumed amount of power use. In so doing, they gain more line harms.
7 0
3 years ago
Other questions:
  • Two small spheres spaced 20.0 cm apart have equal charge. How many excess electrons must be present on each sphere if the magnit
    15·1 answer
  • Use the Divergence Theorem to calculate the surface integral
    9·1 answer
  • Explain how airplane wings and the wings of birds affect the air flowing over them to produce lift
    15·1 answer
  • Difference between matter and energy
    11·1 answer
  • In the two-slit experiment, for the condition of bright fringes, the value of m = +2 corresponds to a path difference of λ.
    6·1 answer
  • When using the lens equation, a negative value as the solution for di indicates that the image is
    13·1 answer
  • A ball of mass 0.5 kg is at point with initial speed 4 m/s at height 10. what is the total energy​
    10·1 answer
  • What two processes are part of electromagnetism?
    11·1 answer
  • 1. A 14-cm tall object is placed 26 cm from a converging lens that has a focal length of 13 cm.
    15·1 answer
  • Element 105 of periodic table
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!