Calculate the mass number of an atom with 8 protons, 12 neutrons and 10 electrons

Physics

1 answer:

Radda [10]3 years ago

7 0

Answer: 20

Explanation: Mass number is the number of neutrons plus the number of protons. 8 + 12 gives 20.

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A positively-charged object with a mass of 0.129 kg oscillates at the end of a spring, generating ELF (extremely low frequency)

9966 [12]

Answer:308 N/m

Explanation:

Given

mass $\left ( m\right )=0.129 kg$

wavelength $\left ( \lambda \right )=3.86\times 10^7$

We know frequency = $\frac{c}{\lambda }=\frac{3\times 10^8}{3.86\tmes 10^7}$

f=7.772 Hz

As the frequency of radio waves is same as the frequency at which object oscillates

$f=\frac{1}{2\pi }\sqrt{\frac{k}{m}}$

$7.772=\frac{1}{2\pi }\sqrt{\frac{k}{0.129}}$

$7.772\times 2\times \pi =\sqrt{\frac{k}{0.129}}$

$k=307.70\approx 308 N/m$

7 0

3 years ago

Your companion on a train ride through Illinois notices that telephone poles near the tracks appear to be passing by very quickl

Nikitich [7]

Answer: Relative motion

Explanation: If two objects are moving either towards or away from each other with both having their velocities in a reference frame and someone is outside this reference frame seeing the motion of the two objects.

The observer ( in his own frame of reference) will measure a different velocity as opposed to the velocities of the two object in their own reference frame. p

Both the velocity measured by the observer in his own reference frame and the velocity of both object in their reference is correct.

Velocities of this nature that have varying values based on motion referenced to another body is known as relative velocity.

Motion of this nature is known as relative motion.

Note that the word reference frame is simply any where the motion is occurring and the specified laws of motion is valid

For this example of ours, the reference frame of the companion is the train and the telephone poles has their reference frame as the earth.

The companion will measure the velocity of the telephone poles relative to him and the velocity of the telephone pole relative to an observer outside the train will be of a different value.

6 0

2 years ago

An apple falls from an apple tree growing on a 20° slope. The apple hits the ground with an impact velocity of 16.2 m/s straight

EleoNora [17]

Apple hits the surface with speed 16.2 m/s

The angle made by the apple velocity with normal to the incline surface is given as 20 degree

now the component of velocity which is parallel to the surface and perpendicular to the surface is given as

$v_{perpendicular} = v cos20$