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3 years ago

I feel like I’ve been on this physics exam forever… please help . NO LINKS.

Physics

1 answer:

sesenic [268]3 years ago

4 0

Explanation:

my guess is A

emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.

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a car drives 40 miles east, turns around, then drives 30 miles west. (a) Find the distance traveled by the car. (b) find the car

Dovator [93]

Part A)

Distance is given as sum of total path length

So here as we are given that car drives 40 miles East and 30 miles West

So here the total path length is

$Distance = 40 miles + 30 miles$

$distance = 70 miles$

Part B)

Displacement is given as straight line distance between initial and final position

So here we can see that

$d_1 = 40 miles$ East

$d_2 = 30 miles$ West

Now the total displacement will be

$d = d_1 - d_2 = 40 - 30 = 10 miles$

<u><em>so the displacement will be 10 miles East</em></u>

8 0

3 years ago

What type of reaction requires the greatest energy to get started? A. fusion B. fission C. physical D. chemical

Vilka [71]

What do u mean by that

4 0

3 years ago

Read 2 more answers

What is the cell emf for the concentrations given? Express your answer using two significant figures.

alisha [4.7K]

Complete Question

A voltaic cell is constructed with two $Zn^{2+}$ $- Zn$ electrodes. The two cell compartment have $[Zn^{2+}] = 1.6 \ M$ and $[Zn^{2+}] = 2.00*10^{-2} \ M$ respectively.

What is the cell emf for the concentrations given? Express your answer using two significant figures

Answer:

The value is $E = 0.06 V$

Explanation:

Generally from the question we are told that

The concentration of $[Zn^{2+}]$ at the cathode is $[Zn^{2+}]_a = 1.6 \ M$

The concentration of $[Zn^{2+}]$ at the anode is $[Zn^{2+}]_c = 2.00*10^{-2} \ M$

Generally the the cell emf for the concentration is mathematically represented as

$E = E^o - \frac{0.0591}{2} log\frac{[Zn^{2+}]a}{ [Zn^{2+}]c}$

Generally the $E^o$ is the standard emf of a cell, the value is 0 V

$E = 0 - \frac{0.0591}{2} * log[\frac{ 2.00*10^{-2}}{1.6} ]$

=> $E = 0.06 V$

4 0

3 years ago

What is the value of -2 + 100 - (-50)?

taurus [48]

I believe the value of -2+100-(50)=148. Hope this helps

3 0

3 years ago

A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 seconds, the angular velocity decreases to

Vladimir [108]

The average angular acceleration of the fan is

$\alpha_{\rm avg}=\dfrac{\Delta\omega}{\Delta t}=\dfrac{200\frac{\rm rev}{\rm min}-1000\frac{\rm rev}{\rm min}}{2\,\rm s}=-6.67\dfrac{\rm rev}{\mathrm s^2}$

The number of revolutions after time $t$ is given by

$\theta=\omega_0t+\dfrac{\alpha}2t^2$

Acceleration is assumed to be constant, so $\alpha=\alpha_{\rm avg}$ and over the 2 second interval we have

$\theta=\left(1000\dfrac{\rm rev}{\rm min}\right)(2\mathrm s)+\dfrac{\alpha_{\rm avg}}2(2\,\mathrm s)^2=20\,\mathrm{rev}$

so the answer is A.

5 0

3 years ago