Ask question

Ask question

All categories

2 years ago

5

Suppose a photon with an energy of 1.60 eV strikes a piece of metal. If the electron that it hits loses 0.800 eV leaving the met

al, what is the kinetic energy of the electron once it has broken free of the metal surface?

1 answer:

JulsSmile [24]2 years ago

7 0

To solve this problem it is necessary to apply the concepts related to the change of Energy in photons and the conservation of energy.

From the theory we could consider that the energy change is subject to

$\Delta E = E_0 -W_f$

Where

$E_0 =$ Initial Energy

$W_f =$ Energy loses

Replacing we have that

$\Delta E = 1.6-0.8$

$\Delta E = 0.8eV$

Therefore the Kinetic energy of the electron once it has broken free of the metal surface is 0.8eV

You might be interested in

A elephant kicks a 5.0\,\text {kg}5.0kg5, point, 0, start text, k, g, end text stone with 150\,\text J150J150, start text, J, en

S_A_V [24]

The speed of the stone is 7.7 m/s

Explanation:

The kinetic energy of a body is the energy possessed by the body due to its motion. Mathematically,

$K=\frac{1}{2}mv^2$

where

m is the mass of the body

v is its speed

For the stone in this problem, we have:

K = 150 J is its kinetic energy

m = 5.0 kg is its mass

Re-arranging the equation for v, we find the speed of the stone:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(150)}{5.0}}=7.7 m/s$

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

3 0

3 years ago

GETTING TIMED PLS HELP! Do the runners in the picture above represent kinetic or potential energy? you need to explain why.

prohojiy [21]

Answer:

<em>They represent kinetic energy</em>

Explanation:

<u>Kinetic Energy </u>

A body can do work due to some of its attributes or states. For example, its mass can do work if used to provide energy, if the object is at a certain height respect to some reference level, it can do work when going downwards (potential energy), if the object moves at a certain speed, it can do work when transferring part of its speed to other objects. It's called kinetic energy and is given by

$\displaystyle K=\frac{mv^2}{2}$

Both runners are moving in a horizontal path, thus they have kinetic energy, given by the above equation. If they could jump below ground level, then they will also have potential energy

8 0

2 years ago

A 35.4 kg girl is riding on the back of a 15.23 kg cart. the cart and the kid are both moving eastward at 4.25 m/s when she step

Grace [21]

Answer:

The final velocity of the cart is $v_c = 7.02 \ m/s$

Explanation:

From the question we are told that

The mass of the girl is $m_g = 35.4 \ kg$

The mass of the cart is $m_c = 15.23 \ kg$

The speed of the cart and kid(girl) is $v = 4.25 \ m/s$

The final velocity of the girl is $v_g = 3.06 \ m/s$

Let assume that velocity eastward is positive and velocity westward is negative (Note that if we assume vise versa it wouldn't affect the answer )

The total momentum of the system before she steps off the back of the cart

is mathematically evaluated as

$p__{T1}} = (m_g + m_c) * v$

substituting values

$p__{T1}} = (35.4 + 15.23) * 4.25$

$p__{T1}} =215.17 \ kg m /s$

The total momentum after she steps off the back of the cart is mathematically evaluated as

$p__{T2}} = (m_g * v_g ) +( m_c * v_c )$

Where $v_c$ is the final velocity of the cart

substituting values

$p__{T2}} = (35.4 * 3.06 ) +( 15.23 * v_c )$

$p__{T2}} = 108. 324 + 15.23 v_c$

Now according to the law of conservation of momentum

$p__{T1}} =p__{T2}}$

So

$215.17 \ kg m /s = 108. 324 + 15.23 v_c$

=> $v_c = 7.02 \ m/s$

Since the value is positive it implies that the cart moved eastward

7 0

3 years ago

Is a measure of how rapidly or slowly molecules move?

horsena [70]

Temperature is a measure of how rapidly or slowly molecules move.<span />

8 0

3 years ago

Read 2 more answers

Turning on a flashlight is what type of energy to what type of energy

MissTica

Turning on a flashlight uses a battery, right? Chemical energy is stored in that battery. If you use the battery, you're converting that chemical energy to an electrical energy.

In a flashlight then, the electrical energy becomes light energy and thermal energy in the bulb. Why light and thermal? The flashlight gives us light and then, gives out heat. This is why when we touch light bulbs, it feels hot.

I hope you find this answer the most helpful! :)

8 0

3 years ago