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
dybincka [34]
3 years ago
8

RACTIC PTUDIES

Physics
1 answer:
Amanda [17]3 years ago
6 0

Answer:

The illumination on the book before the lamp is moved is 9 times the illumination after the lamp is moved.

Explanation:

The distance of the book before the lamp is moved, d_{b} = 30 cm

The distance of the book after the lamp is moved, d_{a} = 90 cm

Illumination can be given by the formula, E = \frac{P}{4 \pi d^{2} }

Illumination before the lamp is moved, E_{b} = \frac{P}{4 \pi d_{b} ^{2} }

Illumination after the lamp is moved, E_{a} = \frac{P}{4 \pi d_{a} ^{2} }

\frac{E_{a}}{E_{b}} } = \frac{\frac{P}{4 \pi d_{a} ^{2} } }{\frac{P}{4 \pi d_{b} ^{2} } }

\frac{E_{a} }{E_{b} } = \frac{d_{b} ^{2} }{d_{a} ^{2}} \\\frac{E_{a} }{E_{b} } = \frac{30^{2} }{90 ^{2}}\\\frac{E_{a} }{E_{b} } =\frac{900 }{8100}\\\frac{E_{a} }{E_{b} } =\frac{1 }{9}

E_{b} = 9E_{a}

The illumination on the book before the lamp is moved is 9 times the illumination after the lamp is moved.

You might be interested in
Newton's 2nf law of motion States that
lapo4ka [179]

Answer:

B (force = mass X acceleration)

Explanation:

The acceleration of an object depends on the mass of the object and the amount of force applied. His second law defines a force to be equal to change in momentum (mass times velocity) per change in time.

Formula: F = m x a

6 0
2 years ago
you throw a rock with a horizontal velocity at 36.6 m/s out a window that is 29.5 m above the ground. What was it’s total time i
ANEK [815]
29.5-4.9x^2= your answer
4 0
3 years ago
What causes the movement of the crust that leads to volcanoes, mountains, and seafloor spreading?
Salsk061 [2.6K]

Answer:

B.convection currents in the mantle

Explanation:

4 0
2 years ago
2. A truck speeds up from a velocity of 6 m/s to 14 m/s in 4 seconds. What is the trucks acceleration? SHOW YOUR WORK
zavuch27 [327]

#2

As it is given here

initial speed is

v_i = 6 m/s

After 4 seconds the final speed is

v_f = 14 m/s

so here we can use the formula of acceleration using kinematics

a = \frac{v_f - v_i}{t}

a = \frac{14 - 6}{4}

a = 2 m/s^2

so here it will accelerate at 2 m/s^2 rate.

#3

As it is given here

initial it starts from rest

v_i = 0 m/s

After 2.5 seconds the final speed is

v_f = 15 m/s

so here we can use the formula of acceleration using kinematics

a = \frac{v_f - v_i}{t}

a = \frac{15 - 0}{2.5}

a = 6 m/s^2

so here it will accelerate at 6 m/s^2 rate.


#4

i think question is not correct as in first line it is saying about a bag of trash and then in next line it is asking for the position of Jumper and bridge.

7 0
3 years ago
the frequency of a beam of uv light is 1.0 ×10 ^15hz what is the energy in one quantum of this light express it in ev? ​
kap26 [50]

Answer:

4.14 eV

Explanation:

f = 1.0 ×10^15 Hz

h= 6.63×10^-34 J s (  this is called PLANCK 'S CONSTANT)

ENEGY = E = ?

E = hf  ( THIS IS FORMULA FOR ENERGY OF ONE QUANTA OR ONE PHOTON )

E= 6.63×10^-34×1.0 ×10^15

E = 6.63×10^-19 J

As 1eV = 1.6×10^-19 J so changing energy in eV from joules we will divide energy by 1.6×10^-19

hence E in eV = 6.63×10^-19/(1.6×10^-19)

          E = 4.14 eV

7 0
3 years ago
Other questions:
  • The energy expenditure value of traveling by car is 3.6 MJ/passenger-kilometer. For one person making a trip of 1000 km, if a ga
    7·1 answer
  • Which of the following solutions should be chosen to help restore an ecosystem naturally? A. reintroducing an animal to the ecos
    11·1 answer
  • What is the difference between velocity and speed??
    5·2 answers
  • Air enters a nozzle steadily at 2.21 kg/m3 and 40 m/s and leaves at 0.752 kg/m3 and 180 m/s. If the inlet area of the nozzle is
    10·1 answer
  • Please help I’m so desperate I’m giving about all my points
    12·1 answer
  • 63. Which of the following types of validity is estab-
    13·1 answer
  • How much force is required to keep 780 n box moving at constant velocity across the floor of the friction force between the box
    10·1 answer
  • Guys pls thi is my last pointa just answer this!!!!(WILL GIVE BRAINLY) A student takes apart a wooden box. What can they build w
    15·1 answer
  • REAL ANSWERS ONLY PLS
    15·1 answer
  • The forces acting on a ball sitting on the ground are
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!