<h2>Hello!</h2>
The answer is: Coulomb's law equation.
<h2>Why?</h2>
The Coulomb's law states that the strength of an electric field (between two charges) can be calculated by multiplying their charges and dividing it into the square of the distance between their centers.
Where:
E = Electric Field Strenght
d = separation between charges (m)
Have a nice day!
Not only in converting temperatures I think, we always use significant figures every time we want to make some experimental report using the exact data from our experiment. If that isn't experimental report ( some exercise/questions from your textbook) it's not necessary
Answer:
<em>The magnetic field's direction is towards the north</em>
<em></em>
Explanation:
The force on a positive charge in a uniform magnetic field is represented by the right hand rule. To determine the direction of the force, place your right hand with your palm up, and your thumb at 90° to the other fingers. If the fingers represent the magnetic field, and the thumb the direction of the positive charge, then the palm will push up in the direction of the force. But a negative charge like an electron pushes in exactly the opposite direction. So if you follow this rule, you will find that the magnetic field points towards the north.
The total momentum of the system has to be conserved to satisfy the principle of conservation of momentum. Before the ball hits the bottle, the momentum of the system is 0.4 x 18 = 7.2 kg m/s
The momentum of the bottle after being hit is 0.2 x 25 = 5 kg m/s
So the momentum of the ball now is 7.2 - 5 = 2.2 kg m/s
Hence its velocity is 2.2/0.4 = 5.5 m/s
