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2 years ago

The speed of light ________ when light goes through glass.

1 answer:

6 0

What happens when the light hits the glass depends on what it was in before it hit the glass.

WHILE it's in the glass, the speed of light doesn't change.

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Two 100 kg bumper cars are moving toward each other in opposite directions. Car A is moving at 8 m/s and Car Bat -10 m/s when th

tatiyna

Answer:

b) -10 m/s

Explanation:

In perfectly elastic head on collisions of identical masses, the velocities are exchanged with one another.

3 0

2 years ago

An electron emitted in the beta decay of bismuth-210 has a mean kinetic energy of 390 keV. (a) Find the de Broglie wavelength of

Sauron [17]

Explanation:

Given that,

The mean kinetic energy of the emitted electron, $E=390\ keV=390\times 10^3\ eV$

(a) The relation between the kinetic energy and the De Broglie wavelength is given by :

$\lambda=\dfrac{h}{\sqrt{2meE}}$

$\lambda=\dfrac{6.63\times 10^{-34}}{\sqrt{2\times 9.1\times 10^{-31}\times 1.6\times 10^{-19}\times 390\times 10^3}}$

$\lambda=1.96\times 10^{-12}\ m$

(b) According to Bragg's law,

$n\lambda=2d\ sin\theta$

n = 1

For nickel, $d=0.092\times 10^{-9}\ m$

$\theta=sin^{-1}(\dfrac{\lambda}{2d})$

$\theta=sin^{-1}(\dfrac{1.96\times 10^{-12}}{2\times 0.092\times 10^{-9}})$

$\theta=0.010^{\circ}$

As the angle made is very small, so such an electron is not useful in a Davisson-Germer type scattering experiment.

4 0

2 years ago

What does the zeroth law of thermodynamics allow us to define?

NeTakaya

It defines that if two thermodynamic systems are each in equilibrium with a third system, then they are in equilibrium with each other.

3 0

3 years ago

Read 2 more answers

A player kicks a soccer ball from ground level and sends it flying at an angle of 30 degrees at a speed of 26 m/s. What is the m

Akimi4 [234]

Answer:

8.6 m

Explanation:

The motion of a soccer ball is a motion of a projectile, with a uniform motion along the horizontal (x-) direction and an accelerated motion along the vertical (y-) direction, with constant acceleration $a=g=-9.8 m/s^2$ towards the ground (we take upward as positive direction, so acceleration is negative).

The initial velocity along the vertical direction is

$v_{y0} = v_0 sin \theta = (26 m/s)(sin 30^{\circ})=13 m/s$

Now we can consider the motion along the vertical direction only. the vertical velocity at time t is given by:

$v_y(t)=v_{y0} +at$

At the point of maximum height, $v_y(t)=0$ , so we can find the time t at which the ball reaches the maximum height:

$0=v_{y0}+at\\t=-\frac{v_{y0}}{a}=-\frac{13 m/s}{-9.8 m/s^2}=1.33 s$

And now we can use the equation of motion along the y-axis to find the vertical position of the ball at t=1.33 s, which corresponds to the maximum height of the ball:

$y(t)=v_{y0}t + \frac{1}{2}at^2=(13 m/s)(1.33 s)+\frac{1}{2}(-9.8 m/s^2)(1.33 s)^2=8.6 m$