conclusion pleaseeee
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Answer:
1. effect of a force -- A force acting on an object causes the object to change its shape or size, to start moving, to stop moving, to accelerate or decelerate.
2. define force -- strength or energy as an attribute of physical action or movement.
3. Force of Friction -- The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. There are at least two types of friction force - sliding and static friction. Though it is not always the case, the friction force often opposes the motion of an object.
3. Types of Friction -- Four Types of Friction
Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases. All four types of friction are described below.
Static Friction
Static friction acts on objects when they are resting on a surface. For example, if you are hiking in the woods, there is static friction between your shoes and the trail each time you put down your foot (see Figure below). Without this static friction, your feet would slip out from under you, making it difficult to walk. In fact, that's exactly what happens if you try to walk on ice. That's because ice is very slippery and offers very little friction.
Friction helps this person to walk
[Figure2]
Q: Can you think of other examples of static friction?
A: One example is the friction that helps the people climb the rock wall in the opening picture above. Static friction keeps their hands and feet from slipping.
Sliding Friction
Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. That's why it's easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil. The pencil “lead” slides easily over the paper, but there's just enough friction between the pencil and paper to leave a mark.
Q: How does sliding friction help you ride a bike?
A: There is sliding friction between the brake pads and bike rims each time you use your bike's brakes. This friction slows the rolling wheels so you can stop.
Rolling Friction
Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards. Ball bearings are another use of rolling friction. You can see what they look like in the Figure below. They let parts of a wheel or other machine roll rather than slide over on another.
Fluid Friction
Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If you've ever tried to push your open hand through the water in a tub or pool, then you've experienced fluid friction. You can feel the resistance of the water against your hand. Look at the skydiver in the Figure below. He's falling toward Earth with a parachute. Resistance of the air against the parachute slows his descent. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. That's why there is greater air resistance against the parachute than the skydiver's body.
5. Advantages of Friction -- Friction is the resistance to motion of one object moving relative to another. There are several types of friction. Some advantages and disadvantages of Friction are given below.
Advantages of Friction:
Friction is responsible for many types of motion
It helps us walk on the ground
Brakes in a car make use of friction to stop the car
Asteroids are burnt in the atmosphere before reaching Earth due to friction.
It helps in the generation of heat when we rub our hands.
Disadvantages of Friction:
Friction produces unnecessary heat leading to the wastage of energy.
The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects.
Forest fires are caused due to the friction between tree branches.