Ask question

Ask question

All categories

3 years ago

11

A very bright source of red light has much more energy than a dim source of blue light. which of these light sources has the bes

t chance of ejecting electrons from a metal surface?

1 answer:

MatroZZZ [7]3 years ago

6 0

Red light has to be the best chance of ejecting electrons from a metal surface

You might be interested in

A 4.5 g coin sliding to the right at 23.8 cm/s makes an elastic head-on collision with a 13.5 g coin that is initially at rest.

Airida [17]

Answer:

a) $v = 11.9\times 10^{-2}\,\frac{m}{s} \,(11.9\,\frac{cm}{s} )$ , b) $\Delta K = 9.559\times 10^{-5}\,J$

Explanation:

a) The final velocity of the 13.5 g coin is found by the Principle of Momentum Conservation:

$(4.5\times 10^{-3}\,kg)\cdot (23.8\times 10^{-2}\,\frac{m}{s} )+(13.5\times 10^{-3}\,kg})\cdot (0\,\frac{m}{s} ) = (4.5\times 10^{-3}\,kg)\cdot (-11.9\times 10^{-2}\,\frac{m}{s} )+(13.5\times 10^{-3}\,kg})\cdot v$

The final velocity is:

$v = 11.9\times 10^{-2}\,\frac{m}{s} \,(11.9\,\frac{cm}{s} )$

b) The change in the kinetic energy of the 13.5 g coin is:

$\Delta K = \frac{1}{2}\cdot (13.5\times 10^{-3}\,kg)\cdot \left[(11.9\times 10^{-2}\,\frac{m}{s} )^{2}-(0\,\frac{m}{s} )^{2}\right]$

$\Delta K = 9.559\times 10^{-5}\,J$

4 0

3 years ago

Read 2 more answers

15. Some people have observed that animal behavior changes just before an earthquake. What might explain this?

Ber [7]

Answer:

15: Animals are able to detect the first of an earthquake's seismic waves—the P-wave, or pressure wave, that arrives in advance of the S-wave, or secondary, shaking wave. This likely explains why animals have been seen snapping to attention, acting confused or running right before the ground starts to shake.

16: No, it is not even remotely true. Microwaves cook food from the outside in, just like a regular oven. In fact, most of the cooking on the inside of the food, depending on its thickness, is done by heat conduction from the outside surfaces inwards, as the microwaves do not actually penetrate that far into the food.

3 0

2 years ago

Which statement correctly describes variable stars?

Kryger [21]

Answer:

D)

Explanation:

The Period-Luminosity relationship tells us that luminosity increases with the period, and of course the more luminosity a star has the more far away they can be seen, so from this we know that:

A) False since lower luminosities can be observed when they are close.

B) False since longer periods means higher luminosities

C) False since lower luminosities can be observed when they are close.

D) True: Variable stars with shorter periods have lower luminosities, so they can only be observed when they are close.

5 0

3 years ago

What two pieces of information do you need to know to get from one location to another?

Tresset [83]

That two information would be "Velocity" & "Time"

We Know = Displacement = Velocity * Time

Hope this helps!

6 0

3 years ago

A 3.39-kg block is sliding down a 7.92-kg frictionless incline. Both are initially moving to the right at 10.3 m/s. q7 (a) If th

Agata [3.3K]

Answer:

Final Speed of Incline = 5.549 m/s

Explanation:

To answer this question, we must remember the fact that any momentum gained by the block is equal to the momentum lost by the incline.

So lets start by find the initial and final momentum of the box in the horizontal direction:

Initial Momentum = mass * initial velocity

Initial Momentum = 3.39 * 10.3 = 34.917 kg*m/s

Final Momentum = mass * final velocity

Final Momentum = 3.39 * 21.4 = 72.546 kg*m/s

Change in momentum: 72.546 - 34.917 = 37.629 kg*m/s

This is equal to the momentum lost by the incline.

Initial momentum of incline = 7.92 * 10.3 = 81.576 kg*m/s

Final momentum of incline = 81.576 - 37.629 = 43.947 kg*m/s

Plugging this into the momentum equation to find the speed:

Final Speed * Mass = Final Momentum

Final Speed = 43.947 / 7.92

Final Speed = 5.549 m/s

3 0

3 years ago