Ask question

Ask question

All categories

3 years ago

5

How much energy is used when the incandescent bulb is left on for 12 hours

1 answer:

Reil [10]3 years ago

3 0

You haven't told us the "wattage" rating of the bulb. We'll just have to call it ' W ' .

The bulb uses energy at the rate of W watts, or 0.001W kilowatts.

In 12 hours, it uses <em>0.012W kilowatt-hours </em>of energy.

= = = = =

W watts = W Joules/second

1 hour = 3600 seconds

12 hours = (12 x 3600) seconds

Energy = (W Joule/sec) x (12 x 3600 sec)

<em>Energy = 43,200W Joules</em>

You might be interested in

How do I count atoms in science

VashaNatasha [74]

Answer:

The "2" tells us that there are 2 hydrogen atoms in this compound.

Explanation:

6 0

3 years ago

Calculate the de Broglie wavelength of: a) A person running across the room (assume 180 kg at 1 m/s) b) A 5.0 MeV proton

solmaris [256]

Answer:

a

$\lambda = 3.68 *10^{-36} \ m$

b

$\lambda_p = 1.28*10^{-14} \ m$

Explanation:

From the question we are told that

The mass of the person is $m = 180 \ kg$

The speed of the person is $v = 1 \ m/s$

The energy of the proton is $E_ p = 5 MeV = 5 *10^{6} eV = 5.0 *10^6 * 1.60 *10^{-19} = 8.0 *10^{-13} \ J$

Generally the de Broglie wavelength is mathematically represented as

$\lambda = \frac{h}{m * v }$

Here h is the Planck constant with the value

$h = 6.62607015 * 10^{-34} J \cdot s$

So

$\lambda = \frac{6.62607015 * 10^{-34}}{ 180 * 1 }$

=> $\lambda = 3.68 *10^{-36} \ m$

Generally the energy of the proton is mathematically represented as

$E_p = \frac{1}{2} * m_p * v^2_p$

Here $m_p$ is the mass of proton with value $m_p = 1.67 *10^{-27} \ kg$

=> $8.0*10^{-13} = \frac{1}{2} * 1.67 *10^{-27} * v^2$

=> $v _p= \sqrt{\frac{8.0 *10^{-13}}{ 0.5 * 1.67 *10^{-27}} }$

=> $v = 3.09529 *10^{7} \ m/s$

So

$\lambda_p = \frac{h}{m_p * v_p }$

so $\lambda_p = \frac{6.62607015 * 10^{-34}}{1.67 *10^{-27} * 3.09529 *10^{7} }$

=> $\lambda_p = 1.28*10^{-14} \ m$

5 0

3 years ago

You are a member of an alpine rescue team and must project a box of supplies, with mass m, up an incline of constant slope angle

AlekseyPX

Answer:

$v = \sqrt{2gh + \frac{2\mu_kgh}{tan\theta}}$

Explanation:

When we push the box from the bottom of the incline towards the top then by work energy theorem we can say that

Work done by all the forces = change in kinetic energy of the system

$- mgh - F_f (s) = 0 - \frac{1}{2}mv^2$

here we know that

$F_f = \mu_k mg cos\theta$

also we know that the length of the incline is given as

$s = \frac{h}{sin\theta}$

now we have

$- mgh - \mu_k mgcos\theta(\frac{h}{sin\theta}) = -\frac{1}{2}mv^2$

so we have

$v = \sqrt{2gh + \frac{2\mu_kgh}{tan\theta}}$

3 0

3 years ago

75% of what number is 27? EXPLAIN

zmey [24]

75 percent (calculated percentage %) of what number equals 27? Answer: 36.

8 0

3 years ago

Read 2 more answers

Please help me and show work, will mark Brainliest!!

Licemer1 [7]

Speed is distance over time, learn that formula and look at the image

3 0

3 years ago