C8: Force and motion
1. What is force? Write its SI unit.
Ans: Force is an external agent that changes or tries to change the state of rest or motion of and object. It can also change the direction of moving bodies, can change the speed of a body and can change the shape and size of an object.
Its SI unit is Newton(N).
2. What are the effects of force?
Ans: The effects of force are:
i. It can change the state of rest or motion of an object.
ii. It can change the direction of moving bodies.
iii. It can change the shape and size of an object.
iv. It can change the speed of a moving body.
3. Define balanced force and unbalanced force with examples.
Ans: Balanced forces are equal in magnitude and opposite in direction. These force can not cause a change in motion. In this case resultant force is always zero. E.g: equal forces applied in opposite direction in tug or war, a book kept at rest on a table etc.
Unbalanced forces are not equal in magnitude and are applied in the opposite direction or sometimes in the same direction. They can cause a change in motion. In this case resultant force is never zero. E.g: a book sliding on an inclined plane, ball rolls in one direction when kicked etc.
4. What is meant by 1N force?
Ans: 1N force is defined as the amount of force applied to a mass of 1 Kg which moves with an acceleration 1 m/s2 in the direction of force.
5. Define Rest and motion with example.
Ans: A body is said to be in rest if it does not change it position with respect to its surrounding objects.
A body is said to be in motion if it changes it position with respect to its surrounding objects.
6. Define uniform motion and write one example of it.
Ans: If a body travels equal distance in equal interval of time the motion of an object is called uniform motion. The motion of heavenly bodies around the sun is an example of uniform motion.
7. What do you mean by vector and scalar quantities? Give two examples of each.
Ans: Vector quantity is the physical quantity which has both magnitude and direction. E.g: force, acceleration etc.
Scalar quantity is the physical quantity which has only magnitude but no direction. E.g: speed, Temperature, density etc.
8. Define distance and displacement with example.
Ans: The total length of path between two points is called distance. It is a scalar quantity.
The shortest length of path between two points is called displacement. It is a vector quantity.
9. What do you mean by seed, uniform speed, velocity, uniform velocity? Give examples of each.
Ans:
10. Define average speed and average velocity.
11. Is velocity a vector or scalar quantity? Give a reason to your answer.
12. Write down the definition of acceleration and retardation.
13. What is uniform acceleration?
14. What do you mean by inertia? On what factor does the inertia of a body depend?
15. Define inertia of rest and inertia of motion.
16. What inertia is present in a stretched rubber?
17. Define mass and weight.
18. What is the relation between mass and inertia of an object?
19. State Newton’s first law of motion. Newton’s first law of motion is also called the law of inertia, explain.
20. State Newton’s second law of motion
21. Prove that F = ma.
22. State Newton’s third law of motion.
23. Explain the action of a rocket on the basis of Newton’s law of motion.
24. Derive the relation v = u + at.
25. Prove that : S = ut + ½ at2
26. Prove that: v2 – u2 = 2as
27. Define momentum with its SI unit.
28. On what factors does momentum of a body depends on?
29. Write the conditions in which acceleration becomes zero.
1. What is force? Write its SI unit.
Ans: Force is an external agent that changes or tries to change the state of rest or motion of and object. It can also change the direction of moving bodies, can change the speed of a body and can change the shape and size of an object.
Its SI unit is Newton(N).
2. What are the effects of force?
Ans: The effects of force are:
i. It can change the state of rest or motion of an object.
ii. It can change the direction of moving bodies.
iii. It can change the shape and size of an object.
iv. It can change the speed of a moving body.
3. Define balanced force and unbalanced force with examples.
Ans: Balanced forces are equal in magnitude and opposite in direction. These force can not cause a change in motion. In this case resultant force is always zero. E.g: equal forces applied in opposite direction in tug or war, a book kept at rest on a table etc.
Unbalanced forces are not equal in magnitude and are applied in the opposite direction or sometimes in the same direction. They can cause a change in motion. In this case resultant force is never zero. E.g: a book sliding on an inclined plane, ball rolls in one direction when kicked etc.
4. What is meant by 1N force?
Ans: 1N force is defined as the amount of force applied to a mass of 1 Kg which moves with an acceleration 1 m/s2 in the direction of force.
5. Define Rest and motion with example.
Ans: A body is said to be in rest if it does not change it position with respect to its surrounding objects.
A body is said to be in motion if it changes it position with respect to its surrounding objects.
6. Define uniform motion and write one example of it.
Ans: If a body travels equal distance in equal interval of time the motion of an object is called uniform motion. The motion of heavenly bodies around the sun is an example of uniform motion.
7. What do you mean by vector and scalar quantities? Give two examples of each.
Ans: Vector quantity is the physical quantity which has both magnitude and direction. E.g: force, acceleration etc.
Scalar quantity is the physical quantity which has only magnitude but no direction. E.g: speed, Temperature, density etc.
8. Define distance and displacement with example.
Ans: The total length of path between two points is called distance. It is a scalar quantity.
The shortest length of path between two points is called displacement. It is a vector quantity.
9. What do you mean by seed, uniform speed, velocity, uniform velocity? Give examples of each.
Ans:
10. Define average speed and average velocity.
11. Is velocity a vector or scalar quantity? Give a reason to your answer.
12. Write down the definition of acceleration and retardation.
13. What is uniform acceleration?
14. What do you mean by inertia? On what factor does the inertia of a body depend?
15. Define inertia of rest and inertia of motion.
16. What inertia is present in a stretched rubber?
17. Define mass and weight.
18. What is the relation between mass and inertia of an object?
19. State Newton’s first law of motion. Newton’s first law of motion is also called the law of inertia, explain.
20. State Newton’s second law of motion
21. Prove that F = ma.
22. State Newton’s third law of motion.
23. Explain the action of a rocket on the basis of Newton’s law of motion.
24. Derive the relation v = u + at.
25. Prove that : S = ut + ½ at2
26. Prove that: v2 – u2 = 2as
27. Define momentum with its SI unit.
28. On what factors does momentum of a body depends on?
29. Write the conditions in which acceleration becomes zero.
Posts
1.Gaurav Neupane: Force is a derived physical quantity. its unit is newton'N'
ReplyDeleteQ1 Aayusha Katwal :Force is an external agents which changes or tends to change the position of a body.
ReplyDeleteThe SI unit of force is Newton(N).
2. Gaurav Neupane:
ReplyDelete1. Its
changes the state of a body.
2.It change sahpe and size of a body
3. It changes the shape and size of a moving body.
Q2 Aayusha Katwal : The effects of force are :
ReplyDelete1) Force can change the speed of of a moving body .
2) Force can change the direction of moving body .
3) Force can change the position of a body.
4) Force can change the shape and size of a body.
5. Gaurav Neupane: Rest:A body is said to be in rest if it doesn't change its position with respect to the surrounding objects. for example:mountains,treesetc
ReplyDeleteMotion:A body said to be in motion if it change its position with respect to the surroundings objects.for eg: moving car,walking etc.
6. Gaurav Neupane:If a body cover equal distances in equal intervals of time then the body is said to be uniform velocity. for example. rotation and evolution of earth.
ReplyDeleteit is not evolution, it is revolution of earth make it correct.
DeleteQ1.sandhya khatiwada: force is an external agent that changes or tends to change the state of rest and motion of an object.
ReplyDelete-The SI unit of force is Newton(N).
Q2.sandhya khatiwada:The effects of force are given below:
ReplyDelete- It changes the state of a body.
-It changes shape and size of a body.
-It changes the direction of a moving body.
-It changes the speed of a moving body
Q3 Aayusha Katwal: A Force where two force of equal size act on a body in opposite direction is known as balanced force.
ReplyDeleteThe force that changes the position ,speed or direction of the object to which it is applied.
ReplyDeleteQ3.sandhya khatiwada:Forces that are equal in size but opposite in direction are called balanced forces. Balanced forces do not cause a change in motion. ..
-Forces that cause a change in the motion of an object are unbalanced forces. Unbalanced force are not equal and opposite.
Q5 Aayusha katwal : A body is said to be rest if it does not change its position with respect to other objects in its surrounding . For example: the trees, building etc.
ReplyDeleteA body is said to be motion if it changes its position with regard to objects in its surrounding . For example : flying kites,vehicles on the road etc.
Q4.Sandhya khatiwada:One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force.
ReplyDeleteQno.1.Sushmita Ghimire:Force is an external agent that changes or tries to change the state of rest or motion of an object.
ReplyDeleteIts SI unit is Newton (N).
ReplyDeleteQ4.Sandhya khatiwada:A body is said to be in rest if it does not change it's position with respect to the surrounding objects. For example:mountains, trees,house etc
- A body is said to be in motion if it changes it's position with respect to the surrounding objects. For examples:a moving car,flying birds,a man walking etc.
Q6 Aayusha Katwal : If a body covers equal distance in an equal interval of time then it is called uniform motion.1 example of uniform motion is movement of a hands of a watch.
ReplyDeleteQno.2.Sushmita Ghimire:The effects of force are:
ReplyDeletea)It changes the state of a body.
b)It changes shape and size of a body.
c)It changes the direction of a moving body.
d)It changes the speed of a moving body.
Q7 Aayusha Katwal: Vector is a physical quantity that has both magnitide and direction . two example are : displacement, force .
ReplyDeleteScalar is a physical quantity which has only magnitude but no direction. Two example are : Mass,speed.
Qno.3.Sushmita Ghimire:Force that are equal in size but opposite in direction are called balanced forces.Balanced forces donot cause a change in motion.
ReplyDeleteForces that cause a change in the motion of an object are called unbalanced forces.Unbalanced force are not equal and opposite.
Q4.Sandhya khatiwada: If a body can cover equal distances in equal interval of time then the body is said to be in uniform motion.for example:A car going along a straight level road at steady speed.
ReplyDeleteA vibrating spring in a sewing machine.
A ship steaming on a straight course at steady speed.etc
Qno.4.Sushmita Ghimire:One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second square in the direvtion of the applied force.
ReplyDeleteQ7.sandhya khatiwada:vector quantity is a physical quantity that has both magnitude and direction. For example: force,displacement.
ReplyDelete-scalar quantity is a physical quantity that has only magnitude but no direction.for example:mass,temperature .
Qno.4.Sushmita Ghimire:One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second square in direction of the applied force.
ReplyDeleteQno.5.Sushmita Ghimire:A body is said to be at rest if it does not change it's position with respect to other objects in it's surrounding.For e.g:mountains,trees,houses etc.
ReplyDeleteA body is said to be in motion if it changes its position with regard to objects in it's surrounding.For e.g:flying birds,planes in the sky,vehicles on the road etc.
Q8 Aayusha Katwal : The length of a path traveled by a moving body in any direction is called distance.For example : five feet between two table .
ReplyDeleteThe shortest distance between two point is called displacement . for example :if a professor moves to the right relative to a white board , or a passenger moves toward the rear of an airplane , then the object changes .
Qno.6.Sushmita Ghimire:If a body covers equal distance in an equal interval of time it is called uniform motion.
ReplyDeleteFor e.g:a car going along a straight level of road at steady speed.
Qno.7.Sushmita Ghimire:Those physical quantity which have both magnitude and direction are called vector quantity.For e.g:Force,velocity etc.
ReplyDeleteThose physical quantity with only magnitude is called scalar quantity.For e.g:mass,time etc.
Qno.8. Sushmita Ghimire:The shortest distance between two points is called displacement.For e.g:if a professor moves to the right relative to a white board,or a passenger moves toward the rear of an airplane,then the object changes.
ReplyDeleteQno.8.Sushmita Ghimire:The length of a path travelled by a moving body in any direction is called distance.For e.g:five feet between two tables,the difference between two sides of an issue etc.
ReplyDeleteQ8 .sandhya Khatiwada:-The length of a path traveled by a moving body in any direction is called distance.For example : five feet between two table etc.
ReplyDelete-The shortest distance between two points is called displacement . for example :if a professor moves to the right relative to a white board , or a passenger moves toward the rear of an airplane , then the object changes.
3.Gaurav Neupane: A force where two force of equal size act on body in opposite direction is known as balanced force.
ReplyDeleteThe force that changes the position,speed,or direction of the object to which it is applied
4.Gaurav Neupane: One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squareed in the direction of the applied force.
ReplyDelete7. Gaurav Neupane: Vector quantity is a physical quantity that has both magnitude and distance.for example.force,displacement.
ReplyDeleteScaler quantity is a physical quantity that has magnitude but no distance. for example.mass , temperature.
Q1=Force is an external agent that changes or tries to change the state of rest or motion of an object.
ReplyDeleteIts SI unit is Newton (N).
Q2=The effects of force are given below:
ReplyDelete- It changes the state of a body.
-It changes shape and size of a body.
-It changes the direction of a moving body.
-It changes the speed of a moving body
Q2=Forces that are equal in size but opposite in direction are called balanced forces. Balanced forces do not cause a change in motion
ReplyDelete-Forces that cause a change in the motion of an object are unbalanced forces. Unbalanced force are not equal and opposite.
Q4=One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second square in direction of the applied force.
ReplyDeleteQ5=A body is said to be at rest if it does not change it's position with respect to other objects in it's surrounding.For e.g:mountains,trees,houses etc.
ReplyDeleteA body is said to be in motion if it changes its position with regard to objects in it's surrounding.For e.g:flying birds,planes in the sky,vehicles on the road etc.
Q6=If a body travels equal distance in equal interval of time the motion of an object is called uniform motion. The motion of heavenly bodies around the sun is an example of uniform motion
ReplyDeleteQ7=Vector quantity is the physical quantity which has both magnitude and direction. E.g: force, acceleration etc.
ReplyDeleteScalar quantity is the physical quantity which has only magnitude but no direction. E.g: speed, Temperature, density etc.
Q8=The total length of path between two points is called distance. It is a scalar quantity.
ReplyDeleteThe shortest length of path between two points is called displacement. It is a vector quantity
Safal kc
ReplyDeleteForce is an external agent that changes or tries to change the state of rest or motion of an object .it's SI unit is Newton N
The effects of force are÷
It can change the state of rest or motion of an object
It can change the direction of moving bodies
It can change the shape of an object
1n force is defined as the amount of force applied to mass. Of 1 kg which moves with an acceleration 1m/s^2 in the direction of force ..
A body is said to be in rest if it doesn't change its position with respect to it's surrounding objects.
A body is said to be in motion if it changes it's position with respect to it's surrounding objects.
If a body travels equal distance in a interval of time ,the motion of heavenly bodies around the sun is an example of uniform velocity ..
Vector quantity is a physical quantity which has both magnitude and direction .
Scalar quantity is a physical quantity which has magnitude but no direction ..
The total length of path between two points is called distance .it is a scalar quantity
The shortest length of path is called displacement .it is a vector quantity.
Acceleration is defined as the rate of change in velocity with time.
A negative acceleration is defined as retardation.
Safal kc