<–2/”>a >Motion
Motion is a change in position of an object with respect to time. Motion is typically described in terms of displacement, distance, velocity, acceleration, time and speed.
The branch of physics which deals with the study of motion of material objects is called mechanics.
Mechanics is divided into following branches.
(i) Statics : Statics is the branch of mechanics which deals with the study of motion of objects under the effect of forces in equilibrium.
(ii) Kinematics :
It is that branch of mechanics which deals with the study of motion of object without taking into account the factors (i.e. nature of forces, nature of bodies etc.) which cause motion. Here time factor plays an essential role.
(iii) Dynamics :
It is that branch of mechanics which deals with the study of motion of objects taking into account the factors whichcause motion.
Rest : An object is said to be at rest if it does not change its position with time, with respect to its surroudings.
A book lying on a table, a person sitting in a chair are the examples of rest.
Motion : An object is said to be in motion if it changes its position with time, with respect to its surroundings.
Example : A bird flying in air, a train moving on rails, a ship sailing on water, a man walking on road are some of the examples of motion, visible to the eye. Motion of gas Molecules is an example of motion, invisible to the eye.
Rest & Motion are relative terms :
When we say that an object is at rest or in motion,then this statement is incomplete and meaningless. Basically, rest & motion are relative terms. An object which is at rest can also be in motion simultaneously. This can be illustrated as follows.
The passengers sitting in a moving bus are at rest with respect to each other but they are also in motion at the same time with respect to the objects like trees, buildings on the road side. So the motion and rest are relative terms.
Rectilinear motion :
If a particle moves in a fixed direction, the motion of this type is called rectilinear motion or one dimensional motion.For example the motion of an ant on a wire is a rectilinear motion.
Two dimensional motion :
If the motion of a particle is in such a way that its position remains on a fixed plane, then the motion of a particle is called two dimensional motion.
Laws Of Motion
First Law of Motion
A body continue to be in its state of rest or of uniform motion along a straight line, unless it is acted upon by some external force to change the state
(1) If no net force acts on a body, then the velocity of the body cannot change i.e. the body cannot accelerate.
(2) Newton‟s first law defines inertia and is rightly called the law of inertia. Inertia are of three types :Inertia of rest, Inertia of motion, Inertia of direction
(3) Inertia of rest : It is the inability of a body to change by itself, its state of rest. This means a body atrest remains at rest and cannot start moving by its own.
Second Law of Motion
(1) The rate of change of linear momentum of a body is directly proportional to the external force appliedon the body and this change takes place always in the direction of the applied force.
(2) If a body of mass m, moves with velocity v then its linear momentum can be given by p= mv and if force is applied on a body, then Force = mass ? acceleration
Third Law of Motion
To every action, there is always an equal (in magnitude) and opposite (in direction) reaction.
(1) When a body exerts a force on any other body, the second body also exerts an equal and opposite forceon the first.
(2) Forces in nature always occurs in pairs. A single isolated force is not possible.
(3) Any agent, applying a force also experiences a force of equal magnitude but in opposite direction. Theforce applied by the agent is called „Action‟ and the counter force experienced by it is called „Reaction‟.
(4) Action and reaction never act on the same body. If it were so the total force on a body would have always been zero i.e. the body will always remain in equilibrium.
(5) If F (AB)= force exerted on body A by body B (Action) and F(BA)= force exerted on body B by body A (Reaction) Then according to Newton‟s third law of motion F (AB) = F(BA)
(6) Example : (i) A book lying on a table exerts a force on the table which is equal to the weight of the book. This is the force of action.,
Motion is the change of position of an object over time. It can be described in terms of its speed, direction, and acceleration.
There are many different types of motion, including rectilinear motion, circular motion, periodic motion, random motion, uniform motion, non-uniform motion, accelerated motion, retarded motion, and projectile motion.
Rectilinear motion is motion in a straight line. Circular motion is motion in a circle. Periodic motion is motion that repeats itself over and over again. Random motion is motion that does not follow any particular pattern. Uniform motion is motion in which the speed is constant. Non-uniform motion is motion in which the speed is not constant. Accelerated motion is motion in which the speed is increasing. Retarded motion is motion in which the speed is decreasing. Projectile motion is the motion of an object that is thrown or launched into the air and then follows a curved path under the influence of gravity.
Force is any interaction that, when unopposed, will change the motion of an object. There are two types of forces: contact forces and non-contact forces. Contact forces are forces that are exerted when two objects touch each other. Non-contact forces are forces that are exerted on objects even though they are not touching each other.
Some examples of contact forces are friction, normal force, tension, and spring force. Friction is a force that opposes the relative motion of two surfaces that are in contact. Normal force is a force that is exerted by a surface on an object that is in contact with it. Tension is a force that is exerted by a rope or cable that is pulling on an object. Spring force is a force that is exerted by a spring when it is stretched or compressed.
Some examples of non-contact forces are Gravitational Force, electrostatic force, and magnetic force. Gravitational force is a force that attracts two objects with mass. Electrostatic force is a force that attracts or repels two objects with electric charge. Magnetic force is a force that attracts or repels two objects with Magnetic Field.
The laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces.
Newton’s first law of motion states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This is also known as the law of inertia.
Newton’s second law of motion states that the acceleration of an object is directly proportional to the net force acting on the object, and inversely proportional to the mass of the object. This is also known as the law of acceleration.
Newton’s third law of motion states that for every action, there is an equal and opposite reaction. This is also known as the law of action and reaction.
The laws of motion are fundamental to our understanding of the physical world. They have been used to explain and predict the motion of objects for centuries, and they continue to be used in many fields of science and engineering today.
What is energy?
Energy is the ability to do work. It can be stored in many different forms, such as heat, Light, Sound, and electricity. Energy can also be transferred from one form to another. For example, when you burn wood, the chemical energy in the wood is converted into heat energy.
What are the different types of energy?
There are many different types of energy, but some of the most common include:
- Kinetic energy: The energy of motion. An object with more kinetic energy will move faster than an object with less kinetic energy.
- Potential energy: The energy stored in an object due to its position or state. For example, a ball held above the ground has potential energy because it could fall and hit the ground.
- Thermal energy: The energy of heat. All objects have some amount of thermal energy, which is caused by the movement of atoms and molecules.
- Chemical energy: The energy stored in chemical Bonds. When chemical bonds are broken or formed, energy is released or absorbed.
- Electrical energy: The energy of electricity. Electricity is a form of energy that can be used to power devices, light homes, and transmit information.
- Nuclear Energy: The energy stored in the nucleus of an atom. Nuclear energy can be released in a nuclear reaction, such as a nuclear fission or nuclear fusion reaction.
What is work?
Work is the transfer of energy from one object to another by means of a force. When you lift a book, you are doing work on the book. The force of your hand is causing the book to move upwards, and this movement is transferring energy from your hand to the book.
What is power?
Power is the rate at which work is done. A more powerful machine can do the same amount of work in a shorter amount of time. For example, a car with a more powerful engine can accelerate faster than a car with a less powerful engine.
What is force?
Force is a push or pull that can cause an object to move, change its shape, or change its speed. The amount of force required to move an object depends on the object’s mass and the acceleration you want to give it. For example, it takes more force to move a heavy object than it does to move a light object.
What are the laws of motion?
The laws of motion are three physical laws that describe the relationship between force, mass, and acceleration. The first law of motion states that an object will remain at rest or in motion at a constant speed in a straight line unless acted upon by an unbalanced force. The second law of motion states that the acceleration of an object is directly proportional to the net force acting on the object, and inversely proportional to the mass of the object. The third law of motion states that for every action, there is an equal and opposite reaction.
What is friction?
Friction is a force that opposes the relative motion of two objects or materials. Friction can be caused by the roughness of the surfaces in contact, or by the adhesion between the surfaces. Friction can be useful, such as when it helps us to walk or drive a car. However, friction can also be a problem, such as when it causes machines to wear out.
What is gravity?
Gravity is a force that attracts all objects with mass to each other. The more mass an object has, the stronger its gravitational pull. The Earth’s gravity is what keeps us on the ground. Gravity also keeps the Moon in orbit around the Earth, and the Earth in orbit around the Sun.
What is inertia?
Inertia is the tendency of an object to resist changes in its motion. An object with more inertia will be more difficult to start moving, stop moving, or change its direction. For example, it is easier to push a small child on a swing than it is to push an adult on a swing.
What is momentum?
Momentum is the product of an object’s mass and velocity. An object with more momentum will have more inertia, and will be more difficult to stop. For example, a car with a lot of momentum will be more difficult to stop than a car with less momentum.
What is energy conservation?
Energy conservation is the principle that energy can neither be created nor destroyed, only transferred from one form to another. For example, when you burn wood, the chemical energy in the wood is converted into heat energy. The heat energy can then be used to cook food or to generate electricity.
What is work-energy theorem?
The work-energy theorem states that the work done on an object is equal to the change in the object’s kinetic energy. For example, if you lift a book, the work you do on the
Sure, here are some MCQs without mentioning the topic Motions, Force, Laws of Motion:
A car is moving at a constant speed. What is the net force acting on the car?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA ball is thrown into the air. What is the net force acting on the ball while it is in the air?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA block is sliding down a ramp. What is the net force acting on the block?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA car is accelerating. What is the net force acting on the car?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA ball is thrown up into the air. What is the net force acting on the ball while it is going up?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA ball is thrown up into the air. What is the net force acting on the ball while it is coming down?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA block is sitting on a table. What is the net force acting on the block?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA block is sliding across a table. What is the net force acting on the block?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA block is falling off a table. What is the net force acting on the block?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motionA block is being pulled across a table by a string. What is the net force acting on the block?
(A) Zero
(B) A constant force in the direction of motion
(C) A constant force in the opposite direction of motion
(D) A variable force in the direction of motion