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
Temka [501]
3 years ago
10

A watt is a measure of power (the rate of energy change) equal to 1 j>s. (a) calculate the number of joules in a kilowatt- ho

ur. (b) an adult person radiates heat to the surroundings at about the same rate as a 100-watt electric incandescent light- bulb. what is the total amount of energy in kcal radiated to the surroundings by an adult in 24 h?
Physics
1 answer:
GalinKa [24]3 years ago
4 0
Before solving this, you must know the definition of these units of measurement. Watt is a measurement of power which is the amount of energy per unit time in seconds. Energy, on the other hand, is expressed through the SI unit Joules. Thus, power is the amount of energy in Joules per second.

From here, you can use the dimensional analysis technique. Also, you should know that 1 kilowatt is equal to 1000 watts, and 24 hours is equal to 86,400 seconds. Then,

100 = Energy/86,400
Energy = 8,640,000 Joules

You might be interested in
A Ferris wheel starts at rest and builds up to a final angular speed of 0.70 rad/s while rotating through an angular displacemen
PilotLPTM [1.2K]

Answer:

The average angular acceleration is 0.05 radians per square second.

Explanation:

Let suppose that Ferris wheel accelerates at constant rate, the angular acceleration as a function of change in angular position and the squared final and initial angular velocities can be clear from the following expression:

\omega^{2} = \omega_{o}^{2} + 2 \cdot \alpha\cdot (\theta-\theta_{o})

Where:

\omega_{o}, \omega - Initial and final angular velocities, measured in radians per second.

\alpha - Angular acceleration, measured in radians per square second.

\theta_{o}, \theta - Initial and final angular position, measured in radians.

Then,

\alpha = \frac{\omega^{2}-\omega_{o}^{2}}{2\cdot (\theta-\theta_{o})}

Given that \omega_{o} = 0\,\frac{rad}{s}, \omega = 0.70\,\frac{rad}{s} and \theta-\theta_{o} = 4.9\,rad, the angular acceleration is:

\alpha = \frac{\left(0.70\,\frac{rad}{s} \right)^{2}-\left(0\,\frac{rad}{s} \right)^{2}}{2\cdot \left(4.9\,rad\right)}

\alpha = 0.05\,\frac{rad}{s^{2}}

Now, the time needed to accelerate the Ferris wheel uniformly is described by this kinematic equation:

\omega = \omega_{o} + \alpha \cdot t

Where t is the time measured in seconds.

The time is cleared and obtain after replacing every value:

t = \frac{\omega-\omega_{o}}{\alpha}

If \omega_{o} = 0\,\frac{rad}{s},  \omega = 0.70\,\frac{rad}{s} and \alpha = 0.05\,\frac{rad}{s^{2}}, the required time is:

t = \frac{0.70\,\frac{rad}{s} - 0\,\frac{rad}{s} }{0.05\,\frac{rad}{s^{2}} }

t = 14\,s

Average angular acceleration is obtained by dividing the difference between final and initial angular velocities by the time found in the previous step. That is:

\bar \alpha = \frac{\omega-\omega_{o}}{t}

If \omega_{o} = 0\,\frac{rad}{s},  \omega = 0.70\,\frac{rad}{s} and t = 14\,s, the average angular acceleration is:

\bar \alpha = \frac{0.70\,\frac{rad}{s} - 0\,\frac{rad}{s} }{14\,s}

\bar \alpha = 0.05\,\frac{rad}{s^{2}}

The average angular acceleration is 0.05 radians per square second.

4 0
3 years ago
Assume that the amplifiers on the stage operate at a combined power of 5,000 Watts, and that 80% of this is converted to sound.
rusak2 [61]

Answer:

0.04

Explanation:

Fraction of power converted to sound = 80% = 0.08

Fraction incident upon each eardrum onstage = 0.08/2 = 0.04

6 0
4 years ago
. Two people are pushing a car of mass 2000 kg.
Viktor [21]

Answer:

two people who are not going to be able to make it to class today because of the day and then I will be there at the house and then we can go

5 0
4 years ago
Which list below contains only ionic compounds?
Vesna [10]
C.
Explanation: ionic compounds are metals and nonmetals, refer to your periodic table
3 0
2 years ago
when 82.5 calories of heat are given to a metallic rod of mass 150g its temperature raises from 20 degree celcius to 25 degree C
marishachu [46]

A 150-g metallic rod with a specific heat of 0.11 cal/g.°C absorbs 82.5 calories of heat and its temperature increases from 20 °C to 25 °C.

<h3>What is specific heat?</h3>

It is the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).

A metallic rod of mass 150 g (m) absorbs 82.5 cal of heat (Q) and its temperature raises from 20 °C to 25 °C. We can calculate the specific heat (c) of the metal using the following expression.

Q = c × m × ΔT

c = Q / m × ΔT

c = 82.5 cal / 150 g × (25 °C - 20 °C) = 0.11 cal/g.°C

A 150-g metallic rod with a specific heat of 0.11 cal/g.°C absorbs 82.5 calories of heat and its temperature increases from 20 °C to 25 °C.

Learn more about specific heat here: brainly.com/question/21406849

#SPJ1

8 0
2 years ago
Other questions:
  • A spring has a spring constant of 53N/m. How much elastic potential energy is stored in the spring in the spring when it is comp
    11·1 answer
  • Oxygen and hydrogen gas are at the same temperature T.What is the ratio of kinetic energies of oxygen molecule and hydrogen mole
    10·1 answer
  • 9. A 2 liter bottle of Coke weighs about 2 kilograms. If that bottle were combined with an equal amount of anti-Coke, how many J
    9·1 answer
  • A CD-ROM is a compact disk that
    12·1 answer
  • A p-type Si sample is used in the Haynes-Shockley experiment. The length of the sample is 2 cm, and two probes are separated by
    5·1 answer
  • Find the acceleration if a 32.5 N force is<br> used on an object that has a mass of<br> 128.6 kg.
    10·1 answer
  • Two tuning forks, 492 Hz and 498 Hz, are struck simultaneously. How many beats will be heard?
    11·1 answer
  • A car of weight 11000 N moves with constant velocity along a horizontal road.A driving force of 5000 N acts on the car what is t
    14·1 answer
  • Can anybody answer this its a science question NO LINKS !!!!
    5·1 answer
  • A toroidal solenoid has 600 turns, cross-sectional area 6.90 cm2, and mean radius 4.30 cm.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!