If you want to do an experiment to see how speed affects a cart’s kinetic energy, what should you do?

A flat sheet of ice has a thickness of 1.4 cm. It is on top of a flat sheet of crown glass that has a thickness of 3.0 cm. Light

MAXImum [283]

Answer:

t = 2.13 10-10 s , d = 6.39 cm

Explanation:

For this exercise we use the definition of refractive index

n = c / v

Where n is the refraction index, c the speed of light and v the speed in the material medium.

The refractive indices of ice and crown glass are 1.13 and 1.52, respectively, therefore the speed of the beam in the material medium is

v = c / n

As the beam strikes perpendicularly, the beam path is equal to the distance of the leaves, there is no refraction, so we can use the uniform motion relationships

v = d / t

t = d / v

t = d n / c

Let's look for the times on each sheet

Ice

t₁ = 1.4 10⁻² 1.31 / 3 10⁸

t₁ = 0.6113 10⁻¹⁰ s

Crown glass (BK7)

t₂ = 3.0 10⁻² 1.52 / 3.0 10⁸

t₂ = 1.52 10⁻¹⁰ s

Time is a scalar therefore it is additive

t = t₁ + t₂

t = (0.6113 + 1.52) 10⁻¹⁰

t = 2.13 10-10 s

The distance traveled by this time in a vacuum would be

d = c t

d = 3 10⁸ 2.13 10⁻¹⁰

d = 6.39 10⁻² m

d = 6.39 cm

3 0

3 years ago

___ devices need constant power to operate. The timing functions are initiated by the presence or absence of a separate ""trigge

Ratling [72]

Answer:

Solid-state

Explanation:

A solid-state device can be defined as a crystalline material that is typically made up of semiconductor and as such controls the number and rate of flow of charged carriers such as holes or electrons.

Some examples of a solid-state device are light emitting diodes (LED), integrated circuit (IC), Transistors, liquid crystal display (LCD) etc.

A solid-state device such as a transistor, refers to a semiconductor component that is used to control the flow of voltage or current and as a gate (switch) for electronic signals. Thus, a transistor allows for the amplification, control and generation of electronic signals in a circuit.

Hence, solid-state devices need constant power to operate. The timing functions are initiated by the presence or absence of a separate "trigger" signal.

Basically, these solid-state devices use the optical and electrical properties of semiconductor components such as transistors, triacs, thyristors, diodes to perform its input-output switching and isolation functions.

6 0

3 years ago

The lowest point in Death Valley is 85 m below sea level. The summit of nearby Mt. Whitney has an elevation of 4420 m.What is th

mario62 [17]

Answer:

$\Delta E=2.87\times 10^6\ J$

Explanation:

It is given that,

Depth of Death valley is 85 m below sea level, $h_i=-85\ m$

The summit of nearby Mt. Whitney has an elevation of 4420 m, $h_f=4420\ m$

Mass of the hiker, m = 65 kg

We need to find the change in potential energy. It is given by :

$\Delta E=mg(h_f-h_i)$

$\Delta E=65\times 9.8(4420-(-85))$

$\Delta E=2869685\ J$

or

$\Delta E=2.87\times 10^6\ J$

So, the change in potential energy of the hiker is $2.87\times 10^6\ J$ . Hence, this is the required solution.

5 0

3 years ago

A 0.0250-kg bullet is accelerated from rest to a speed of 550 m/s in a 3.00-kg rifle. The pain of the rifle’s kick is much worse

kondaur [170]

Answer:

a) 4.583 m/s

b) 31.505 J

c) 0.491 m/s

d) 3.375 J

e)

p_player = (110 kg)(8 m/s) = 880 kg m/s

p_ball = (0.41 kg)(25 m/s) = 10.25 kg m/s

Explanation:

HI!

a)

We can calculate the recoil velocity by conservation of momentum, remember that p=mv.

The momentum of the bullet is:

p_b = (0.0250 kg)*(550 m/s )

The momentum of the rifle is:

p_r = (3 kg) * v

Since the total initial momentum is zero:

p_b = p_r

That is:

v = (550 m/s ) (0.0250 kg/ 3 kg ) = 4.583 m/s

b)

The kinetic energy gained by the rifle is:

K = (1/2) m v^2 = (1/2) *(3 kg) *(4.583 m/s)^2 = 31.505 J

c)

We use the same formula as in a), but with m=28kg instead of 3 kg

v = (550 m/s ) (0.0250 kg/ 28 kg ) = 0.491 m/s

d)

Again, the same formula as b, but with m=28 and v=0.491 m/s

K = 3.375 J

e)

p_player = (110 kg)(8 m/s) = 880 kg m/s

p_ball = (0.41 kg)(25 m/s) = 10.25 kg m/s

I believe that the kinetic energy is more related to the problem than the momentum. The relation between these two quantities is:

K = p^2/(2m)

usiing this relation, we get:

K_player = 3520 J

K_ball = 128.125 J

Therefore the kinetic energy of the player is around 27 time larger than the kinetic energy of the ball, that being said, the pain of being tackled by that player is around 27 times greater that being hit by the ball!

4 0

3 years ago

A yellow and green car traveled 400 miles to Dayton, OH. The green car made the trip in 10 hours. The yellow arrived in 8 hours.

elixir [45]

Answer: C)The yellow car was faster. Yellow traveled at a speed of 50 mph while green was traveling at an average of 40 mph.

Explanation:

The speed of each car is defined as:

$v=\frac{d}{t}$