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3 years ago

For each of the following statements, determine whether it is true or false.

Physics

1 answer:

Oksanka [162]3 years ago

6 0

Answer:

1) True: Spring A is stiffer than B (kA > kB). Less work must be expended on spring A if both springs are stretched by the same amount.

2) False: The kinetic energy of an object depends on the direction of the motion involved.

3) True: The work done to raise a box onto a platform does not depend on how fast it is raised.

4) True: The friction force is a non-conservative force.

5) True: The kinetic energy can be negative.

6) False: The kinetic energy does not depend on the reference frame of the observer.

7) False: Work can be done in the absence of motion.

8) False: If the moon revolves around the earth in a perfectly circular orbit, then the earth does do work on the moon.

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What does Einstein's famous equation for nuclear energy, E = mc^2, mean?

Nezavi [6.7K]

Yup the correct answer is A jus finished the quiz :)

hope i helped^_^

8 0

3 years ago

Two inductors, L1 and L2, are in parallel. L1 has a value of 25 mH and L2 a value of 50 mH. The parallel combination is in serie

Bond [772]

Answer:

Explanation:

For parallel inductors ,

$\frac{1}{L_R} = \frac{1}{L_1} +\frac{1}{L_2}$

$\frac{1}{L_R} =\frac{1}{25} +\frac{1}{50}$

$L_R=16.67 mH.$

For series combination

Total inductance

= 16.67 + 20

= 36.67 mH .

reactance of total inductance at 300 kHz

= ω $L_{total}$ where ω is angular frequency

= 2πf $L_{total}$

= 2 x 3.14 x 300 x 10³ x 36.67 x 10⁻³

= 69.1 x 10³ ohm

Total rms current = Vrms / reactance

= 60 / 69.1 x 10³ A

= .87 x 10⁻³ A

= .87 mA

7 0

3 years ago

What is the energy per photon absorbed during the transition from n = 2 to n = 3 in the hydrogen atom?

adelina 88 [10]

Answer : The energy of one photon of hydrogen atom is, $3.03\times 10^{-19}J$

Explanation :

First we have to calculate the wavelength of hydrogen atom.

Using Rydberg's Equation:

$\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )$

Where,

$\lambda$ = Wavelength of radiation

$R_H$ = Rydberg's Constant = 10973731.6 m⁻¹

$n_f$ = Higher energy level = 3

$n_i$ = Lower energy level = 2

Putting the values, in above equation, we get:

$\frac{1}{\lambda}=(10973731.6)\left(\frac{1}{2^2}-\frac{1}{3^2} \right )$

$\lambda=6.56\times 10^{-7}m$

Now we have to calculate the energy.

$E=\frac{hc}{\lambda}$

where,

h = Planck's constant = $6.626\times 10^{-34}Js$

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength = $6.56\times 10^{-7}m$

Putting the values, in this formula, we get:

$E=\frac{(6.626\times 10^{-34}Js)\times (3\times 10^8m/s)}{6.56\times 10^{-7}m}$

$E=3.03\times 10^{-19}J$

Therefore, the energy of one photon of hydrogen atom is, $3.03\times 10^{-19}J$

3 0

3 years ago

How does tightening a string on a guitar affect its natural frequency?

iragen [17]

By tightening a string you are actually putting more stress on the string you are giving it a new frequency that isn't natural.

Hope this helps

3 0

4 years ago

Read 2 more answers

What mRNA sequence would result from the following DNA sequence?

Nezavi [6.7K]

Answer:

UAC CUG AGG AUC

Explanation:

The mRNA sequence from ATG GAC TCC TAG DNA sequence would be UAC CUG AGG AUC.

According to Chargaff's base pairing rule, the purine bases always pair with pyrimidine bases. Specifically, Adenine base must pair with Thymine base while Guanine base must pair with Cytosine base. In RNA, Thymine base is replaced with Uracil base.

Hence:

ATG GAC TCC TAG will pair with

UAC CUG AGG AUC

5 0

3 years ago