Which of the following should NOT be discussed during safety training

Which of the following has to happen for Earth's shadow to fall on the moon?

Ronch [10]

The correct answer is a, lunar eclipse

6 0

3 years ago

For a damped simple harmonic oscillator, the block has a mass of 1.2 kg and the spring constant is 9.8 N/m. The damping force is

ArbitrLikvidat [17]

Answer:

a) t=24s

b) number of oscillations= 11

Explanation:

In case of a damped simple harmonic oscillator the equation of motion is

m(d²x/dt²)+b(dx/dt)+kx=0

Therefore on solving the above differential equation we get,

x(t)=A₀ $e^{\frac{-bt}{2m}}cos(w't+\phi)=A(t)cos(w't+\phi)$

where A(t)=A₀ $e^{\frac{-bt}{2m}}$

A₀ is the amplitude at t=0 and

$w'$ is the angular frequency of damped SHM, which is given by,

$w'=\sqrt{\frac{k}{m}-\frac{b^{2}}{4m^{2}} }$

Now coming to the problem,

Given: m=1.2 kg

k=9.8 N/m

b=210 g/s= 0.21 kg/s

A₀=13 cm

a) A(t)=A₀/8

⇒A₀ $e^{\frac{-bt}{2m}}$ =A₀/8

⇒ $e^{\frac{bt}{2m}}=8$

applying logarithm on both sides

⇒ $\frac{bt}{2m}=ln(8)$

⇒ $t=\frac{2m*ln(8)}{b}$

substituting the values

$t=\frac{2*1.2*ln(8)}{0.21}=24s(approx)$

b) $w'=\sqrt{\frac{k}{m}-\frac{b^{2}}{4m^{2}} }$

$w'=\sqrt{\frac{9.8}{1.2}-\frac{0.21^{2}}{4*1.2^{2}}}=2.86s^{-1}$

$T'=\frac{2\pi}{w'}$ , where $T'$ is time period of damped SHM

⇒ $T'=\frac{2\pi}{2.86}=2.2s$

let $n$ be number of oscillations made

then, $nT'=t$

⇒ $n=\frac{24}{2.2}=11(approx)$

8 0

4 years ago

(a) What is the current involved when a truck battery sets in motion 720 C of charge in 4.00 s while starting an engine? (b) How

OLEGan [10]

Answer:

(a) Current flowing through truck battery is 180 A

(b) Time taken in calculator is 333.33 s

Explanation:

(a) Given:

The charge on the truck battery,q = 720 C

Time, t = 4.00 s

Consider I be the current flowing through truck battery.

The relation between current, charge and time is:

I = q/t

Substitute the suitable values in the above equation.

$I=\frac{720}{4}$

I = 180 A

(b) Given:

The charge on the calculator,q = 7.00 C

The current flowing through calculator, I = 0.3 mA = 0.3 x 10⁻³ A

Consider t be the time.

The relation between current, charge and time is:

t = q/I

Substitute the suitable values in the above equation.

$t=\frac{1}{0.3\times10^{-3} }$

I = 333.33 s

8 0

4 years ago

With what type of electromagnetic radiation would you observe:

Viefleur [7K]

Answer:

Green part of the visible spectrum.

X ray part of the electromagnetic spectrum.

Infrared part of the electromagnetic spectrum.

Explanation:

Wien's displacement law

$\lambda_{max}=\frac{b}{T}$

Where, b = Wien's displacement constant = 2.898×10⁻³ mK

T = Temperature in kelvin

$\lambda_{max}=\frac{2.898\times 10^{-3}}{5800}\\\Rightarrow\lambda_{max}=0.499\times 10^{-6}=0.5\mu m=500\ nm$

So, the wavelength would be of around the green part of the visible spectrum.

$\lambda_{max}=\frac{2.898\times 10^{-3}}{1\times 10^6}\\\Rightarrow\lambda_{max}=2.898\times 10^{-9}=2.898\ nm$

So, the wavelength would be of around the X ray part of the electromagnetic spectrum.

Human body temperature = 37°C = 37+273.15 = 310.15 K

$\lambda_{max}=\frac{2.898\times 10^{-3}}{37+273.15}\\\Rightarrow\lambda_{max}=\frac{2.898\times 10^{-3}}{310.15}\\\Rightarrow\lambda_{max}=9.34\times 10^{-6}=934\ nm$

So, the wavelength would be of around the Infrared part of the electromagnetic spectrum.

5 0

3 years ago

A fission reaction is one in which the weaker electrostatic repulsion force wins out over the ___________ nuclear force and, as

natulia [17]

The answer is b. Strong

6 0

4 years ago

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