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3 years ago

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A stationary boat in the ocean is experiencing waves from a storm. The waves move at 59 km/h and have a wavelength of 145 m . Th

e boat is at the crest of a wave. .How much time elapses until the boat is first at the trough of a wave?

1 answer:

krek1111 [17]3 years ago

5 0

Answer:

The time elapses until the boat is first at the trough of a wave is 4.46 seconds.

Explanation:

Speed of the wave, v = 59 km/h = 16.38 m/s

Wavelength of the wave, $\lambda=145\ m$

If f is the frequency of the wave. The frequency of a wave is given by :

$v=f\lambda\\\\f=\dfrac{v}{\lambda}\\\\f=\dfrac{16.38\ m/s}{145\ m}\\\\f=0.112\ Hz$

The time period of the wave is given by :

$T=\dfrac{1}{f}\\\\T=\dfrac{1}{0.112\ Hz}\\\\T=8.92\ s$

We need to find the time elapses until the boat is first at the trough of a wave. So, the time will be half of the time period of the wave.

$T=\dfrac{8.92}{2}\\\\T=4.46\ s$

Hence, this is the required solution.

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Consider a transformer. used to recharge rechargeable flashlight batteries, that has 500 turns in its primary coil, 3 turns in i

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<em>c) 2.304 Watts</em>

Explanation:

A transformer is used to step-up or step-down voltage and current. It uses the principle of electromagnetic induction. When the primary coil is greater than the secondary coil, the it is a step-down transformer, and when the primary coil is less than the secondary coil, the it is a step-up transformer.

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<em></em>

b) by law of energy conservation,

$I_{P}V_{p} = I_{s}V_{s}$

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$I_{p}$ = input current = ?

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120 $I_{p}$ = 3.2 x 0.72

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<em></em>

c) power input = $I_{p} V_{p}$

==> 0.0192 x 120 = <em>2.304 Watts</em>

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