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
Ipatiy [6.2K]
3 years ago
15

Number 29 plz help physics

Physics
1 answer:
svetoff [14.1K]3 years ago
8 0

Answer:

a. E = 900000 J = 900 KJ

b. ΔT = 8.18 °C

c. Cost = $ 7.2  

Explanation:

a.

The energy can be given by:

E = Pt

where,

E = Energy = ?

P = Power = 500 W

t = time = (0.5 h)(3600 s/1 h) = 1800 s

Therefore,

E = (500\ W)(1800\ s)

<u>E = 900000 J = 900 KJ</u>

b.

The change in temperature of room air is given by the following formula:

0.5E = mC\Delta T\\   (since 50% of energy is used to heat air)

where,

m = mass of air = 50 kg

C = specific heat of air = 1.1 KJ/kg.°C

ΔT = Change in temperature of air = ?

Therefore,

(0.5)(900\ KJ) = (50\ kg)(1.1\ KJ/Kg.^oC)\Delta T

<u>ΔT = 8.18 °C</u>

c.

First, we will calculate the total energy consumed:

E = (0.5\ KW)(6\ h/d)(30\ d)\\E = 90\ KWh

Now, for the cost:

Cost = (Unit\ Cost)(Energy)\\Cost = (\$ 0.08\KWh)(90\ KWh)

<u>Cost = $ 7.2</u>

You might be interested in
For a 50 kV anode voltage, what is the maximum photon energy of the x-ray radiation?
V125BC [204]

Answer:

The energy of photon, E=8\times 10^{-15}\ J

Explanation:

It is given that,

Voltage of anode, V=50\ kV=50\times 10^3\ V=5\times 10^4\ V

We need to find the maximum energy of the photon of the x- ray radiation. The energy required to raise an electron through one volt is called electron volt.

E=eV

e is charge of electron

E=1.6\times 10^{-19}\times 5\times 10^4

E=8\times 10^{-15}\ J

So, the maximum energy of the x- ray radiation is 8\times 10^{-15}\ J. Hence, this is the required solution.

6 0
3 years ago
An object moves in a circle with a period of 0.025 hours. What is its frequency in Hz?
Sedaia [141]

Answer:

40 Hz

Explanation:

f = 1/T = 1 / 0.025 = 40 Hz

7 0
3 years ago
I am a give awayer please like this and say thanks
s344n2d4d5 [400]

Answer:

what.....................

i edited this answer

please mark me as brainlist

4 0
3 years ago
Read 2 more answers
What color visions can dog see
chubhunter [2.5K]
I'm pretty sure its d. because depends what tipe of dog it is there are some that see different colors so I'm pretty sure its d.
6 0
3 years ago
An object at rest will ______ unless acted upon by an unbalanced force.
zvonat [6]

Answer:

It's C because if you were trying to put it at rest that means you would put it on a Balanced surfest

4 0
2 years ago
Read 2 more answers
Other questions:
  • We're can I get a life
    12·2 answers
  • B⃗ is kept constant but the coil is rotated so that the magnetic field, B⃗ , is now in the plane of the coil. How will the magne
    8·2 answers
  • How much work must be done to stop a 1075-kg car traveling at 115 km/h ? Express your answer to two significant figures and incl
    15·1 answer
  • With what minimum speed must you toss a 130 g ball straight up to just touch the 14-m-high roof of the gymnasium if you release
    13·1 answer
  • Lynn rubs a balloon with a piece of wool, which causes the balloon to pick up some of the electric charges from the wool. Lynn t
    9·2 answers
  • The entropy of an isolated system must be conserved, so it never changes.a. Trueb. Fasle
    13·1 answer
  • L. What does it mean to "convert" from one unit to another? Give an example.
    6·2 answers
  • Conveyor belts are often used to move packages around warehouses. The conveyor shown below moves packages at a steady 4.0 m/s. A
    11·1 answer
  • Which is an example of current electricity?
    11·1 answer
  • Net force and acceleration
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!