Use Coulomb law: F = k * q1*q2 / (r^2), where k = 9.00 * 10^9 N.m^2/C^2

F = 9.00 * 10^9 N.m^2/C^2 * 2.4*10^-8 C * 1.8*10^-6 C / [0.008m]^2 = 38.88 * 10^ -5 N

F = 39 * 10 -5N

4 0

3 years ago

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A soccer ball is kicked and travels 25 meters to the north in 4 seconds. At what velocity is the ball traveling?

storchak [24]

Answer:

Explanation:

v = d/t

v = 25 m / 4 s

v = 6.25 m/s north

4 0

3 years ago

Diagnostic ultrasound of frequency 4.50 MHz is used to examine tumors in soft tissue. (a) What is the wavelength in air of such

mafiozo [28]

(a) $7.62 \times 10^{-5} m$ is the wavelength in air of such a sound wave.

(b) $3.33 \times 10^{-4}\ m$ is the wavelength of this wave in tissue.

<u>Explanation:</u>

Frequency and wavelength can be related by the equation,

Velocity = Wavelength x Frequency

$v=\lambda \times f$

where,

v - velocity of light for all EM (electromagnetic) waves in vacuum

Given:

f - 4.50 MHz = $4.50 \times 10^{6} \mathrm{Hz}$

a) To find the wavelength in air

We know,

Speed of sound in air = 343 m/s

Apply given frequency and speed of sound in air, we get

$\lambda=\frac{v}{f}=\frac{343}{4.5 \times 10^{6}}=76.2 \times 10^{-6}=7.62 \times 10^{-5}\ \mathrm{m}$

b) If the speed of sound in tissue is 1500 m/s, find the wavelength of this wave in tissue

Speed of sound in tissue, v = 1500 m/s

$\lambda=\frac{v}{f}=\frac{1500}{4.5 \times 10^{6}}=333.33 \times 10^{-6}=3.33 \times 10^{-4} \mathrm{m}$

4 0

3 years ago

You need to know the height of a tower, but darkness obscures the ceiling. You note that a pendulum extending from the ceiling a

Drupady [299]

U gotta add like all of them bro

3 0

3 years ago