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3 years ago

Find the initial kinetic energy, the final kinetic energy, and the change in kinetic energy for the first 2.00 m of fall.

1 answer:

4 0

<span>Find the initial kinetic energy, the final kinetic energy, and the change in kinetic energy for the first 2.00 m of fall.</span>

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A block is at rest on a plank whose angle can be varied. The angle is gradually increased from 0 deg. At 31.8°, the block starts

galina1969 [7]

Answer:

$\mu_s = 0.62$

$\mu_k = 0.415$

The motion of the block is downwards with acceleration 1.7 m/s^2.

Explanation:

First, we will calculate the acceleration using the kinematics equations. We will denote the direction along the incline as x-direction.

$x - x_0 = v_0t + \frac{1}{2}at^2\\3.4 = 0 + \frac{1}{2}a(2)^2\\a = 1.7~m/s^2$

Newton’s Second Law can be used to find the net force applied on the block in the -x-direction.

$F = ma\\F = 1.7m$

Now, let’s investigate the free-body diagram of the block.

Along the x-direction, there are two forces: The x-component of the block’s weight and the kinetic friction force. Therefore,

$F = mg\sin(\theta) - \mu_k mg\cos(\theta)\\1.7m = mg\sin(31.8) - \mu_k mg\cos(31.8)\\1.7 = (9.8)\sin(\theta) - mu_k(9.8)\cos(\theta)\\mu_k = 0.415$

As for the static friction, we will consider the angle 31.8, but just before the block starts the move.

$mg\sin(31.8) = \mu_s mg\cos(31.8)\\\mu_s = tan(31.8) = 0.62$

5 0

3 years ago

One of the primary goals of the Kepler space telescope is to search for Earth-like planets. Data gathered by the telescope indic

amid [387]

Answer:

85.62 m

168.75 years

101.04 years

Explanation:

$L_0$ = Length of ship = 143 m

v = Velocity of ship = 0.8c

c = Speed of light

s = Distance to Boralis orbit = 135 ly

Gamma value

$\gamma=\dfrac{1}{\sqrt{1-\dfrac{v^2}{c^2}}}\\\Rightarrow \gamma=\dfrac{1}{\sqrt{1-\dfrac{0.8^2c^2}{c^2}}}\\\Rightarrow \gamma=1.67$

Length contraction is given by

$L=\dfrac{L_0}{\gamma}\\\Rightarrow L=\dfrac{143}{1.67}\\\Rightarrow L=85.62\ m$

The length is 85.62 m

Time taken

$t=\dfrac{s}{v}\\\Rightarrow t=\dfrac{135}{0.8}\\\Rightarrow t=168.75\ years$

Time taken from the perspective one Earth is 168.75 years

Time dilation is given by

$t'=\dfrac{t}{\gamma}\\\Rightarrow t'=\dfrac{168.75}{1.67}\\\Rightarrow t'=101.04\ years$

The time taken from the perspective of the ship is 101.04 years

8 0

4 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

Find the wavelength of the third line in the lyman series, and identify the type of em radiation.

Natalija [7]

The wavelength of the third line in the Lyman series, and identify the type of EM radiation

In this series, the spectral lines are obtained when an electron makes a transition from any high energy level (n=2,3,4,5... ). The wavelength of light emitted in this series lies in the ultraviolet region of the electromagnetic spectrum.

1 / lambda = R(h)* ( $\frac{1}{(n1)^{2} }$ - $\frac{1}{(n2)^{2} }$ )