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3 years ago

Calculate the acceleration of a turtle going from 0.3 m/s to 0.7 m/s in 30 seconds.

1 answer:

6 0

Acceleration = velocity/ time
Acceleration = 0.7-0.3 /30= 0.01 m/s^2
Notice that velocity is calculated the final speed minus the initial !

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Green light travels by what type of wave? (2 points) a Conductive b Electronic c Conducive d Electromagnetic

antiseptic1488 [7]

Answer: d. Electromagnetic wave

Explanation:

Light is an electromagnetic wave, no matter is wavelength or color.

In this sense, the main characteristic of this type of wave is that it can propagate trhough vacumm, it is not necessary a medium. In addition, electromagnetic waves are transversal waves, this means the electric field oscillates in all normal directions to the direction of wave propagation.

8 0

3 years ago

Read 2 more answers

Electron spin: Radio astronomers can detect clouds of hydrogen too cool to radiate optical wavelengths of light by means of the

Ivan

Answer:

the magnetic field experienced by the electron is 0.0511 T

Explanation:

Given the data in the question;

Wavelength λ = 21 cm = 0.21 m

we know that Bohr magneton μ $_B$ is 9.27 × 10⁻²⁴ J/T

Plank's constant h is 6.626 × 10⁻³⁴ J.s

speed of light c = 3 × 10⁸ m/s

protein spin causes magnetic field in hydrogen atom.

Initial potential energy = -μ $_B$ B × cos0°

= -μ $_B$ B × 1

= -μ $_B$ B

Final potential energy = -μ $_B$ B × cos180°

= -μ $_B$ B × -1

= μ $_B$ B

so change in energy will be;

ΔE = μ $_B$ B - ( -μ $_B$ B )

ΔE = 2μ $_B$ B

now, difference in energy levels will be;

ΔE = hc/λ

2μ $_B$ B = hc/λ

2μ $_B$ Bλ = hc

B = hc / 2μ $_B$ λ

so we substitute

B = [(6.626 × 10⁻³⁴) × (3 × 10⁸)] / [2(9.27 × 10⁻²⁴) × 0.21 ]

B = [ 1.9878 × 10⁻²⁵ ] / [ 3.8934 × 10⁻²⁴ ]

B = 510556326.09

B = 0.0511 T

Therefore, the magnetic field experienced by the electron is 0.0511 T

7 0

3 years ago

The voltage across the terminals of an ac power supply varies with time according to V=V0cos(t). The voltage amplitude is V0 = 4

kirza4 [7]

Answer:

A) V_rms = 29 V

B) Vav = 0 V

Explanation:

A) We are told that;

V = V_o cos ωt

voltage amplitude; V = V_o = 41.0V

Now, the formula for the root-mean-square potential difference Vrms is given as;

V_rms = V/√2

Thus plugging in relevant values, we have;

V_rms = 41/√2

V_rms = 29 V

B) Due to the fact that the voltage is sinusoidal from the given V = V_o cos ωt, we can say that the average potential difference Vav between the two terminals of the power supply would be zero.

Thus; Vav = 0 V

5 0

3 years ago

A tradesman sharpens a knife by pushing it with a constant force against the rim of a grindstone. The 30-cm-diameter stone is sp

Lorico [155]

Answer:

a. 0.21 rad/s2

b. 2.205 N

Explanation:

We convert from rpm to rad/s knowing that each revolution has 2π radians and each minute is 60 seconds

200 rpm = 200 * 2π / 60 = 21 rad/s

180 rpm = 180 * 2π / 60 = 18.85 rad/s