Force and Pressure Flashcards
How does force come in to play?
At least two objects must interact for a force to come into play. Thus, an interaction of one object with another object results in the force between two objects.
How to find net force of an object?
Forces applied on an object in same direction add to one another whereas if the two forces act in the opposite directions on an object the net force acting on it is the difference between the two forces.
How is force expressed?
The strength of force is usually expressed by its magnitude.
How does force bring a change in the state of motion of an object? what is it?
A change in either the speed of an object or its direction of motion or both is described as change in a state of motion. Thus, a force may bring a change in the state of motion.
The application of force on an object may change which characteristics?
The application of force on an object may :
- make an object move from rest
-change the speed of an object if its moving
-change the direction of motion of an object
-bring about change in the shape of an object
-cause some or all of these effects
What is a muscular force?
The type of contact force resulting in the action of muscles is known as the muscular force.
What is friction? what is it responsible for?
The force of friction is contact force which always acts on all the moving objects and its direction is always opposite to the direction of motion since the force of friction arises due to contact between services it is also an example of contact the force of friction is contact force which always acts on all the moving objects and its direction is always opposite to the direction of motion since the force of friction arises due to contact between services it is also an the force of friction is contact force which always acts on all the moving objects and its direction is always opposite to the direction of motion.
It is the force responsible for changing the state of motion of objects in all the above examples in this chapter.
What is a non contact force? name its types.
A non contact force doesn’t have to be in contact for its application. There are three types of non contact forces which are: magnetic force, electrostatic force and gravitational force.
Describe magnetic force.
It is the force exerted by magnetic field of an object. It is a non contact force as a magnet can exert force on another magnet without being in contact with it.
What is electrostatic force?
The force exerted by charged body on another charged or uncharged body is known as electrostatic force. This force comes into play when the bodies are not in contact, the electrostatic force therefore, an another example of non- contact force.
What is gravity and what is the force of gravity?
Objects are things falls towards the earth because it pulls them this force is called force of gravity it is present in all mass objects in universe whether small or large. It depends upon the mass of the object the higher the mass, the higher the gravity and lower the mass, lower the gravity. This is an attractive force the force of gravity at the point all objects of the earth without us being aware of it.
What is pressure?
The force acting on a unit area of a unit area of a surface is called pressure.
= Pressure is equal to force / area on which it acts.
Why do porters in a railway station put a cloth roll on their heads?
By doing this they increase the area of contact of the load with the head, so, the pressure on the heads is reduced and they find it easier to carry the load.
Why is the broader part of the nail is difficult to insert in the wall than the sharper point of a nail
Because the smaller the area larger the pressure on the surface for the same force.
Prove that liquids and gases also exert pressure.
The pressure exerted by liquids and gases is called as fluid friction or drag.
Liquid : Take a bottle full of water and put holes on its surface, the water starts to flow out of the holes, which indicates the pressure of liquids on the walls of the container.
Gas : when we put holes in an inflated balloon the air starts to flow out or when we try to inflate a balloon with holes, it is not possible. This indicates that gases exert pressure on the walls of their container and find ways to get out of it.
