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.)
Answer:
Sliding friction is the force that sliding objects experience
Explanation:
Answer: part a: 19.62m
part b: 19.62 m/s
part a: 2.83 secs
Explanation:If the air resistance is ignored then the swimmer experience free fall under gravity hence
u=0
a=9.81 m/s2
t=2 secs
s=h
Part b
Part c
now we have h=2*19.62=39.24
Answer:
Explanation:
When a body is held against a vertical wall , to keep them in balanced position , normal force is applied on their surface . this force creates normal reaction which acts against the normal force and it is equal to the normal force as per newton's third law . Ultimately friction force is created which is proportional to normal force and it acts in vertically upward direction . It prevents the body from falling down .
Hence normal force = reaction force .
From second law also net force is zero , so if normal force is N and reaction force is R
R - N = mass x acceleration = mass x 0 = 0
R = N .
Ranking normal force from highest to smallest
150 N , 130 N , 120 N
B )
Frictional force is equal to the weight of the body because the body is held at rest .
Ranking of frictional force form largest to smallest
7 kg , 5 kg , 3 kg , 1 kg .
Here frictional force is irrespective of the normal force acting on the body because frictional force adjusts itself so that it becomes equal to weight in all cases here because it always balances the weight of the body .
