All categories

3 years ago

One kilowatt-hour is equal to which of these values?

2 answers:

8 0

One kilowatt-hour = 1000 watts = 1000 joules/second
One hour = 60 × 60 = 3600 seconds

One kWh = 3600 × 1000 joules
One kWh = 36 × 100000 joules
One kWh = 3.6 × 10 × 100000 joules
One kWh = 3.6 × 10⁶ joules

Answer: Second option

Phoenix [80]3 years ago

4 0

The answer is B #platousers

You might be interested in

The resistivity of gold is 2.44 x 10-8 ohms.m at room temperature. A gold wire that is 0.9 mm in diameter and 14 cm long carries

harkovskaia [24]

Answer:

E=0.036 V/m

Explanation:

Given that

Resistivity ,ρ=2.44 x 10⁻⁸ ohms.m

d= 0.9 mm

L= 14 cm

I = 940 m A = 0.94 A

We know that electric field E

E= V/L

V= I R

R=ρL/A

So we can say that

E= ρI/A

Now by putting the values

$E=\dfrac{ 2.44\times 10^{-8}\times 0.94}{\dfrac{\pi}{4}(0.9\times 10^{-3})^2}$

E=0.036 V/m

6 0

3 years ago

Web Spiders and Oscillations All spiders have special organs that make them exquisitely sensitive to vibrations. Web spiders det

chubhunter [2.5K]

Complete Question

The complete quetion is shown on the first uploaded image

Answer:

Explanation:

From the question we are told that

The mass of the fly is $m_f = 11 mg = 11*10^{-3} g = 1.1*10^{-5} \ kg$

The extension of the web is $e= 4.00 \ mm = 0.004 \ m$

The spring constant is mathematically evaluated as

$k = \frac{mg}{e}$

substituting values

$k = \frac{1.1 *10^{-5} *9.8}{0.004}$

$k = 0.027 \ N/m$

The frequency of vibration is

$f = \frac{1}{2 \pi} \sqrt{\frac{k}{m} }$

substituting values

$f = \frac{1}{2 * 3.142 } \sqrt{\frac{0.027}{1.1*10^{-5}} }$

$f = 7.9 Hz$

8 0

3 years ago

5) A person holds a 1.7 kg bucket and lets it move down at

Elena L [17]

Answer:

12.5J

Explanation:

Given parameters:

Mass of bucket = 1.7kg

Height = 75cm = 0.75m

Unknown;

Work done on the bucket by the person = ?

Solution:

To solve this problem, we use the work done equation;

Work done = force x distance = mgh

m is the mass

g is the acceleration due to gravity

h is the height

Now, insert parameters and solve ;

Work done = 1.7 x 9.8 x 0.75 = 12.5J

7 0

3 years ago

A plane flies from base camp to lake a, 200 km away in the direction 20.0° north of east. after dropping off supplies it flies t

Liono4ka [1.6K]

Distance of lake a is 200 km at 20 degree north of east

distance between lake a and b is 230 km at 30 degree west of north

now the distance between base and lake b is given as

$d = d_1 + d_2$

given that

$d_1 = 200 cos20 i + 200 sin20 j$

$d_1 = 187.94 i + 68.4 j$

$d_2 = -230 sin30 i + 230 cos30 j$

$d_2 = -115 i + 199.2 j$

now the total distance is

$d = (187.94 - 115)i + (199.2 + 68.4)j$

$d = 72.94 i + 267.6 j$

now the magnitude of the distance is given as

$d = \sqrt{72.94^2 + 267.6^2}$

$d = 277.4$

also the direction is given as

$\theta = tan^{-1}\frac{267.6}{72.94}$

$\theta = 74.7 degree$

<em>so it is 277.4 km at 74.7 degree North of East</em>

8 0

3 years ago

Leia is presenting her project about gravity to her class. She says that both mass and distance affect how strong the gravitatio

DaniilM [7]

Answer:

No, because as distance increases, gravitional force decreases.

5 0

4 years ago