Lecture-3
Physics
1. The turning effect of the a force on a body is known as __________.- The Moment of Force or Torque
2. Which kind of quantity is Torque ?-Vector
3. Momentum of Force = Force * Perpendicular Distance of the Force from the Axis of Rotation
4. What is the Class -1 of Lever ?- A Class 1 lever has the fulcrum placed between the effort and load. The movement of the load is in the opposite direction of the movement of the effort. This is the most common lever configuration.
5. What is the Class-2 of Lever ?- A Class 2 lever has the load between the effort and the fulcrum. In this type of lever, the movement of the load is in the same direction as that of the effort.
6. What is the Class-3 of Lever ?- A Class 3 lever has the effort between the load and the fulcrum. Both the effort and load are in the same direction.
7. Example of Lever of Class-1 -Scissors , Sea Saw , Brakes of Cycle, , hand Pump, Plass
8. Examples of Lever of Class-2 - Nut Cracker and Waste Carrying Machine
9. Examples of Lever of Class-3?- Tong, Man’s Hand and Tiller
URL for Details : https://www.school-for-champions.com/machines/levers_classess.htm#.XNTjK-UzbIU
10. In which year the Newton explained Law of Gravitation ?- 1686 AD
11. How did Newton Explained the Law of Gravitation ?- Newton explained that in the Universe each particle of matter attracts every other particle. This universal attractive force is called gravitation.
PROPERTIES OF GRAVITATION
12. It is always attractive in nature. Thus , it is never repulsive.
13. It is the weakest force but is a long range force.
14. Mathematically it is represented as FG = GMm/r2
15. Explanation to Formula
· G –Gravitational Constant
· M- Mass of the First Particle
· m= Mass of the Second Particle
· r= It is distance between the said particles.
16. What is the value of Gravitational Constant ?- 6.67 * 10 -11 N*m2 / Kg2
17. What is Gravity ?- It is the force by which the Earth attracts a body towards its Centre.
18. What is Acceleration due to Gravity ?- It is the rate of increase of velocity of a body falling freely towards the Earth. It is represented by g.
19. What is the mathematical representation of Acceleration due to Gravity ?-g = GMe/ Re2
20. Explanation to Formula
· Me = Mass of the Earth
· Re = Radius of Earth
21. What is value of g at the surface of Earth ?- 9.8 m/s2
22. What is the reason of existence of atmosphere on earth ?- Gravity
23. The value of g on the Moon is _______ of that on the Earth Surface ?- 1/6th
24. When we go above the surface of the Earth , the acceleration due to gravity goes on _________- Decreasing
25. When we go below the surface of the Earth , the acceleration due to gravity goes on _________. Decreasing
26. The acceleration due to gravity is ________ proportional to the distance of object from the earth’s surface ?- Inversely
27. At what point the acceleration due to gravity becomes zero ?- Centre of the Earth
28. While decreasing the rotational motion of Earth , the value of g _______- Increases
29. When we go from equator to the poles the value of g goes on ________-Increasing
30. If the Earth stops its rotation about its own axis , then at the equator the value of g ________, consequently the weight of body _______- Increases, increases.
31. ________ is defined as force acting normally on unit area of surface.- Pressure
32. Formula for Pressure - Normal Force /Area
33. What is the unit to measure pressure ?- N/m2
34. What is the alternate name of the N/m2 ?- Pascal
35. Which kind of quantity is Pascal ?- Scalar
36. What is the formula of pressure in liquid ? - p = ρgh,
37. Explanation to Formula :
· p = Pressure
· ρ = Density of the liquid
· h = Height
· g = Acceleration Due to Gravity
38. Atmospheric pressure of 1 atm = 1.018 * 105 N/m2 = 760 torr
39. __________is a unit of pressure based on an absolute scale.– Torr
40. Atmospheric pressure _________ with altitude- Decreases
41. Natural effects of fall in the atmosphere :
· Difficulty in Cooking
· Leakage of the Fountain Pen
42. Which instrument is used for measuring atmospheric pressure ?- Barometer
43. If there is rise in the reading of the barometer , it indicates ____________- Clear Weather
44. The sudden fall in the barometric reading is the indicator of ________- Storm
45. Slow fall in the barometric reading is the indicator of _______- Rainfall
46. ________ is defined as the ratio of its mass (M) to its volume (V).
Density = Mass/Volume
47. What is the Unit of Density ?- Kg/m3
48. Density of water is maximum at ______- 4 o C
49. __________ is defined as the ratio of the density of the substance to the density of water at 4 o C. –Relative Density
50. Formula of Relative Density = Density of Substance / Density of Water at 4 oC