Initial momentum = 2 * m v
so if 1 ball popped out with 2 v momentum would be conserved
but the initial kinetic energy of the two balls is
1/2 m v^2 + 1/2 m v^2 = m v^2
But the kinetic energy of one ball with twice the speed would be
KE = 1/2 m (2 v)^2 = 2 m v^2 thus violating conservation of energy
See for yourself how the forces of electricity and magnetism can work together by building a simple DC electric motor using simple materials you can find in any hardware store!
Electricity and magnetism are both forces caused by the movement of tiny charged particles that make up atoms, the building blocks of all matter. When a wire is hooked up to a battery, current flows through the wire because negatively charged electrons flow from the negative terminal of the battery toward the positive terminal of the battery because opposite charges attract each other, while similar charges repel each other. This flow of electrons through the wire is an electric current, and it produces a magnetic field.
In a magnet, atoms are lined up so that the negatively charged electrons are all spinning in the same direction. Like an electric current, the movement of the electrons creates a magnetic force. The area around the magnet where the force is active is called a magnetic field. Metal objects and other magnets that enter this field will be pulled toward the magnet.
The way the atoms are lined up creates two different poles in the magnet, a north pole and a south pole. As with electrical charges, opposite poles attract each other, while like poles repel each other.
Learn about electromagnetism and its many uses here.
Now let's watch it work as we build a motor.
(Note: This science project requires adult supervision.)
The answer would be D, negative acceleration
Answer:
Option B is correct.
A double insulated drill generally has a plastic case with the electrical connections and motor insulated within the tool
Explanation:
A double insulated drill's design in real life has plastic casing as the insulator & it wouldn't be a drill without its motor now, would it!?
Explanation:
The efficiency of a machine is 70% means 30% of the applied force is wasted in overcoming friction and 70% of the applied force is used to do the work
