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
Serga [27]
3 years ago
13

A light bulb has a power output of 80 W and it has been left on for 90 seconds. How much work was done?

Physics
1 answer:
Karo-lina-s [1.5K]3 years ago
3 0

7200 joules of heat and light energy was dissipated into the air. But no work was done ... no force moved through no distance.

You might be interested in
Which of the following is true about plants and cellular energy?
kkurt [141]

Answer:

D

Explanation:

6CO² + 6H²O > sunlight, chlorophyll, enzymes > C⁶H¹²O⁶ + 6O²

3 0
3 years ago
Starting circuit One battery. 2 light bulbs in parallel; switch What is the voltage across the battery? What is the voltage acro
balu736 [363]

Answer:

The voltage across light bulb 1 and light bulb 2 is the the same i.e V

Explanation:

In a parallel circuit, the Voltage is same across all the components of the circuit and the current flowing through each component is added to get the total current across the circuit.

Let us say, the voltage across the circuit is V. The voltage across light bulb 1 and light bulb 2 is the the same i.e V

5 0
3 years ago
An electric iron is used to remove wrinkles from clothing. The electric iron is made of metal. Which property of this substance
Hoochie [10]

Answer:

d

Explanation:

the heat can move through the metal and onto the clothing

7 0
3 years ago
:)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
FromTheMoon [43]

Good morning dear...

Have a beautiful and joyful day ahead.

6 0
2 years ago
Steam in a heating system flows through tubes whose outer diameter is 5 cm and whose walls are maintained at a temperature of 13
svet-max [94.6K]

Answer:

5945.27 W per meter of tube length.

Explanation:

Let's assume that:

  • Steady operations exist;
  • The heat transfer coefficient (h) is uniform over the entire fin surfaces;
  • Thermal conductivity (k) is constant;
  • Heat transfer by radiation is negligible.

First, let's calculate the heat transfer (Q) that occurs when there's no fin in the tubes. The heat will be transferred by convection, so let's use Newton's law of cooling:

Q = A*h*(Tb - T∞)

A is the area of the section of the tube,

A = π*D*L, where D is the diameter (5 cm = 0.05 m), and L is the length. The question wants the heat by length, thus, L= 1m.

A = π*0.05*1 = 0.1571 m²

Q = 0.1571*40*(130 - 25)

Q = 659.73 W

Now, when the fin is added, the heat will be transferred by the fin by convection, and between the fin and the tube by convection, thus:

Qfin = nf*Afin*h*(Tb - T∞)

Afin = 2π*(r2² - r1²) + 2π*r2*t

r2 is the outer radius of the fin (3 cm = 0.03 m), r1 is the radius difference of the fin and the tube ( 0.03 - 0.025 = 0.005 m), and t is the thickness ( 0.001 m).

Afin = 0.006 m²

Qfin = 0.97*0.006*40*(130 - 25)

Qfin = 24.44 W

The heat transferred at the space between the fin and the tube will be:

Qspace = Aspace*h*(Tb - T∞)

Aspace = π*D*S, where D is the tube diameter and S is the space between then,

Aspace = π*0.05*0.003 = 0.0005

Qspace = 0.0005*40*(130 - 25) = 1.98 W

The total heat is the sum of them multiplied by the total number of fins,

Qtotal = 250*(24.44 + 1.98) = 6605 W

So, the increase in heat is 6605 - 659.73 = 5945.27 W per meter of tube length.

5 0
3 years ago
Other questions:
  • What is a scientist studying if she is interested in the flow of energy, heat, and work?
    7·2 answers
  • Jenny and Betty are having a great time at Busch Gardens riding the Ubanga Banga bumper cars. Jenny, who is traveling southward
    10·1 answer
  • LASIK eye surgery uses pulses of laser light to shave off tissue from the cornea, reshaping it. A typical LASIK laser emits a 1.
    15·1 answer
  • a high speed train travels with an average speed of 250 km/h. the train travels for 2 hrs. how far does the train travel
    10·2 answers
  • Explain what physicists mean when they say that the de Broglie wavelength relates to the probability distribution wave function.
    13·1 answer
  • What is pmolecule and hmolecules
    6·1 answer
  • Who thinks there is a 9th planet (not counting Pluto) and tell me why
    8·1 answer
  • What is denser medium?​
    7·1 answer
  • Define mixture, heterogeneous, homogeneous, solution, colloid, suspension, solvent, solute, saturation.( please don't answer the
    10·2 answers
  • It takes 500W of power to move an object 96 m in 12 s. What force is being applied to the object?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!