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QveST [7]
3 years ago
14

A lightbulb has a power of 100 W and is used for 4 hours. A microwave has a power of 1200 W and is used for 5 minutes. How much

energy is used by the lightbulb? How much energy is used by the microwave? The lightbulb has an efficiency of 1.8%. How much heat energy does the lightbulb produce in 4 hours?
Physics
1 answer:
ladessa [460]3 years ago
4 0

Answer:

a. E=1440KJ

b. E=360KJ

c. E=1.8 J

Explanation:

I have the power (Watts) is expressed as Energy (Joules) / Time (seconds), also I have to1hour * \frac{60min}{1hour}*\frac{60s}{1min}\\1h=3600s

so, for the lightbulb

100W= \frac{Energy}{3600s*4}\\Energy=100W*14400s\\ E=1440000J =1440KJ

Analogously, for the microwave

1200W= \frac{Energy}{60s*5}\\Energy=1200W*300s\\ E=360000J =360KJ

Now, I have to express the efficiency as Heat energy / power * 100 so1.8= \frac{Heat Energy}{100W}*100\\Heat Energy=1.8J

Done

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In the process of loading a ship, a shipping container gets dropped into the water and sinks to the bottom of the harbor. Salvag
jolli1 [7]

Answer:

57.885.8 kg   weight of the container

Explanation:

The volume of the balloon * density of water = buoyant force of balloon

 volume of a sphere = 4/3 pi r^3

                                   = 4/3 pi * (1.5)^3 = 14.14 m^3   <===balloon volume

Now,   find the buoyant force on the container ALONE ....

             5.8 * 2.6 * 2.8  * 1027  = 43 364  kg   <=====  buoyant force

Now add the buoyant force of the balloon to find the weight

             43 364  +   14.14 * 1027 = 57885.8   kg

3 0
2 years ago
How are seeds different from spores?
andrew11 [14]

Explanation:

1.<u>Seeds have endosperm which provides nourishment for a new plant, but spores do not have any stored food supplies.</u>

hope it helpful

3 0
3 years ago
An object in projectile motion will follow which path? a]curved up from the ground b]curved down toward the ground c]straight do
Lesechka [4]
It's B because when you throw something it doesn't go up it slowly descends downward
7 0
3 years ago
Read 2 more answers
A clamp-type measuring instrument operates on the principle of
Hitman42 [59]

<em>A clamp-type measuring instrument operates on the principle of; </em>

A. induction

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3 years ago
Show that the optimal launch angle for a projectile subject to gravity is 45o by carrying out the following steps: 6. Write down
Lorico [155]

Answer:

sin  2θ = 1    θ=45

Explanation:

They ask us to prove that the optimal launch angle is 45º, for this by reviewing the parabolic launch equations we have the scope equation

            R = Vo² sin 2θ / g

Where R is the horizontal range, Vo is the initial velocity, g the acceleration of gravity and θ the launch angle. From this equation we see that the sine function is maximum 2θ = 90 since sin 90 = 1 which implies that θ = 45º; This proves that this is the optimum angle to have the maximum range.

We calculate the distance traveled for different angle

          R = vo² Sin (2 15) /9.8

          R = Vo² 0.051 m

In the table are all values ​​in two ways

Angle (θ)                  distance R (x)

 0                 0                     0

15                 0.051 Vo²        0.5 Vo²/g

30                0.088 vo²        0.866   Vo²/g

45                0.102 Vo²        1   Vo²/g

60                0.088 Vo²      0.866   Vo²/g

75                0.051 vo²        0.5   Vo²/g

90                0                     0

See graphic ( R Vs θ)  in the attached ¡, it can be done with any program, for example EXCEL

6 0
3 years ago
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