Calculate the amount of energy produced in joules by 100- watt light bulb lit for 2.5 hours.

A 50-kg cart is on an incline of 30 degrees above the horizontal. The cart is at rest. The static coefficient of the slope is 0.

sesenic [268]

The cart is at rest, so it is in equilibrium and there is no net force acting on it. The only forces acting on the cart are its weight (magnitude w), the normal force (mag. n), and the friction force (maximum mag. f ).

In the horizontal direction, we have

n cos(120º) + f cos(30º) = 0

-1/2 n + √3/2 f = 0

n = √3 f

and in the vertical,

n sin(120º) + f sin(30º) + (-w) = 0

n sin(120º) + f sin(30º) = (50 kg) (9.80 m/s²)

√3/2 n + 1/2 f = 490 N

Substitute n = √3 f and solve for f :

√3/2 (√3 f ) + 1/2 f = 490 N

2 f = 490 N

f = 245 N

(pointed up the incline)

4 0

3 years ago

A)If the rms value of the electric field in an electromagnetic wave is doubled, by what factor does the rms value of the magneti

Ghella [55]

A) The magnetic field doubles as well

The relationship between rms value of the electric field and rms value of the magnetic field for an electromagnetic wave is the following:

$E_{rms}=cB_{rms}$

where

E_rms is the magnitude of the electric field

c is the speed of light

B_rms is the magnitude of the magnetic field

From the equation, we see that the electric field and the magnetic field are directly proportional: therefore, if the rms value of the electric field is doubled, then the rms value of the magnetic field will double as well.

B) The intensity will quadruple

The intensity of an electromagnetic wave is given by

$I=\frac{1}{2}c\epsilon_0 E_0^2$

where

c is the speed of light

$\epsilon_0$ is the vacuum permittivity

$E_0$ is the peak intensity of the electric field

The rms value of the electric field is related to the peak value by

$E_{rms}=\frac{E_0}{\sqrt{2}}$

So we can rewrite the equation for the intensity as

$I=c\epsilon_0 E_{rms}^2$

we see that the intensity is proportional to the square of the rms value of the electric field: therefore, if the rms value of the electric field is doubled, the average intensity of the wave will quadruple.

7 0

3 years ago

Compare the outermost electrons of an atom with the inner most electrons of an atom in terms of energy

iris [78.8K]

The innermost electron of an atom has the lowest level of energy while the outermost electron has the highest level of energy.
There are different energy levels in the atoms of elements, for an atom to go into an higher level it has to obtain more energy and to go to lower level it has to lose energy.

8 0

4 years ago

A 2.99 x 10-6 C charge is moving in a

Ksenya-84 [330]

Answer:

824 m/s

Explanation:

Acellus

3 0

3 years ago

Read 2 more answers

42.5 Quiz: The Rock Cycle

Snowcat [4.5K]

Answer: It formed when lava cooled quickly aboveground.

Explanation: Cause its right

8 0

3 years ago