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poizon [28]
3 years ago
12

A laptop can convert 400J of electrical energy into a 240J of light and sound. What is the efficiency? Where does the rest of th

e energy go?
Physics
1 answer:
Blababa [14]3 years ago
8 0
Efficiency = (Wanted) energy out ÷ energy in × 100

Energy in = 400J
Wanted Energy out = 240J

Energy cannot be used up, only transferred, so the remaining energy is most likely to be transferred into unwanted energy (loss of energy) such as heat energy.

Efficiency = 240 ÷ 400 × 100
Efficiency = 0.6 × 100
Efficiency = 60%
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Plz help idk and it's due tomorrow
____ [38]
1) G. The continents are now farther apart. 2) A. P waves. They usually travel 60% faster than S waves. 3) H. A hot spot caused the Hawaiian Islands to form.
7 0
3 years ago
Read 2 more answers
If the magnitude of the electric field in air exceeds roughly 3 ✕ 106 n/c, the air breaks down and a spark forms. for a two-di
Vlad1618 [11]

Answer: 39.8 μC

Explanation:

The magnitude of the electric field generated by a capacitor is given by:

E = \frac{V}{d}

d is the distance between the plates.

For a capacitor, charge Q = CV where C is the capacitance and V is the voltage.

C =\frac{\epsilon_o A }{d}

where A is the area of the plate and ε₀ is the absolute permittivity.

substituting, we get

E = \frac{Q}{\epsilon_o A}

It is given that the magnitude of the electric field that can exist in the capacitor before air breaks down is, E = 3 × 10⁶ N/C.

radius of the plates of the capacitor, r = 69 cm = 0.69 m

Area of the plates, A = πr² = 1.5 m²

Thus, the maximum charge that can be placed on disks without a spark is:

Q = E×ε₀×A

⇒ Q = 3 × 10⁶ N/C × 8.85 × 10⁻¹² F/m × 1.5 m² = 39.8 × 10⁻⁶ C = 39.8 μC.

8 0
3 years ago
A satellite is launched to orbit the Earth at an altitude of 3.25 107 m for use in the Global Positioning System (GPS). Take the
Korolek [52]

Answer:Orbital period =21.22hrs

Explanation:

given that

mass of earth M = 5.97 x 10^24 kg

radius of a satellite's orbit, R=  earth's radius + height of the satellite

6.38X 10^6 +  3.25 X10^7 m =3.89 X 10^7m

Speed of satellite, v= \sqrt GM/R

where G = 6.673 x 10-11 N m2/kg2

V= \sqrt (6.673x10^-11 x 5.97x10^ 24)/(3.89 X 10^ 7m)

V =10,241082.2

v= 3,200.2m/s

a) Orbital period

\sqrt GM/R = \frac{2\pi r}{T}

V= \frac{2\pi r}{T}

T= 2 \pi r/ V

= 2 X 3.142 X 3.89 X 10^7m/ 3,200.2m/s

=76,385.1 s

60 sec= 1min

60mins = 1hr

76,385.1s =hr

76,385.1/3600=21.22hrs

3 0
3 years ago
If 0.250 L of a gas weighs 0.308 g under normal conditions of pressure and temperature, what is its molecular weight?
Phantasy [73]

Answer:

=28

Explanation:

.25/22=0,11 mol

0.308/0,11=28

8 0
3 years ago
Solving:
STatiana [176]

Answer:

1. 31,536,000 seconds

2. Car B traveled a longer distance

3. Volume of box = 0.235887 cubic meters

Explanation:

Q1. Age in seconds

1 year = 365 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds

Therefore 1 year = 365 x 24 x 60 x 60 = 31,536,000 seconds

In scientific notation this would be 3.1536\times  10^7 \text{ seconds}

Q2. Comparing km and miles

Given:
1 km = 1000m and 1 m = 3.3ft,   I km = 1000 x 3.3 = 3300 ft.

Convert Car A distance of 25.7km to feet :
25.7 km. = 25. 7 x 3300 ft. = 84,810 ft.

For Car B  that traveled 20 miles,
20 miles = 20 x 5280 = 105,600 ft.

Since 105,600 > 84,810, car B traveled a longer distance

Q3. Volume of wooden box

The wooden box is in the shape of a rectangular prism
It volume is L x W x H
Volume = 1.525 x 0.30 x 0.5156 = 0.235887 cubic meters

5 0
11 months ago
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