Answer:
Work = F * s where s is the distance F moves
Since F is stationary, in this case, "no work" is done by either person
Electrons: negative charge
Protons: positive charge
Neutrons: negative charge
The atom would have to have more electrons than protons
Hope this helps :)
The emerging velocity of the bullet is <u>71 m/s.</u>
The bullet of mass <em>m</em> moving with a velocity <em>u</em> has kinetic energy. When it pierces the block of wood, the block exerts a force of friction on the bullet. As the bullet passes through the block, work is done against the resistive forces exerted on the bullet by the block. This results in the reduction of the bullet's kinetic energy. The bullet has a speed <em>v</em> when it emerges from the block.
If the block exerts a resistive force <em>F</em> on the bullet and the thickness of the block is <em>x</em> then, the work done by the resistive force is given by,

This is equal to the change in the bullet's kinetic energy.

If the thickness of the block is reduced by one-half, the bullet emerges out with a velocity v<em>₁.</em>
Assuming the same resistive forces to act on the bullet,

Divide equation (2) by equation (1) and simplify for v<em>₁.</em>

Thus the speed of the bullet is 71 m/s
Answer:
<h2>velocity = 12.73 km/hr.</h2><h2 />
Explanation:
velocity = distance / time
=<u> 28 km </u>
2.2 hr
= 12.73 km/hr.
Answer:
B. The escape speed of the Moon is less than that of the Earth; therefore, less energy is required to leave the Moon.
Explanation:
Since the speed required to escape from the gravitational attraction of the Moon is less than the speed required to escape from the gravitational attraction of the Earth, less energy is required to travel from the Moon to the Earth, than is required to travel from the Earth to the Moon. This is because the kinetic energy is directly proportional to the square of the velocity.