Students and Teacher's Forum

Students and Teachers Forum

As we know, radius OB is perpendicular to tangentAB So triangle OAB is right angle triangle. hence we can use pythagoraus theorem Let y be the radius. OA 2 = OB2 + AB2 or,(y + 8)2 = y 2+ 162 Now simplify and get .....

2. A car of mass 1000 kg starts to move from rest and covers a distance of 100 m by the application of a restaurant force of 500N. Calculate its acceleration. What is the time taken by it to move through this distance? Also find the final velocity of the car.

Then, collect the informations you have got, to claculate the time taken (t) and final velocity (v). You have calculated the value of acceleration (a). The car starts from rest. So, the initial velocity (u) = 0 m/s. The distance .....

3. A dog pulls a sledge of 50 kg with a force of 100N against the 60N friction. How much is the acceleration of the sledge?

Here, the force applied by the dog to pull the sledge is 100N. The dog pulls the sledge against 60N friction. So, 60N of the force applied is wasted due to the friction. Thus, the net force used to pull the sledge (F) is 100N - 60N = .....

4. A ball is thrown upward with a velocity of 20m/s. Calculate the maximum height reached by the ball and how long does it remain in the air?(g = 9.8 m/s²).

The ball stops when it reaches the maximum height, and then returns back to the ground. So, the final velocity for the rising phase (v) is .....

5. A lever lifts a load of 500N when an effort of 125N is applied on it. Calculate its MA.

Here, the load lifted by the lever (L) is given as 500N And, the effort applied (E) is given as 125N. You have to calculate the mechanical advantage (MA) of the lever. For this, you can use the formula, MA = L/E. Can you find the .....

6. How much salary does a man receive in the 9^th year and also find the total salary for 9 years if his annual salary was Rs 2000 with an increment of Rs 200 in each year?

Here we have given that, annual salary is Rs.2000, incriment is Rs. 200 in each year We need to find total salary at the end of 9th year. For this, a = Rs.2000 d = rs.200 And n = 9 So total salary = S9 = n /2 .....

7. In the adjoining Venn diagram, S, N and M denote the college students who like Sony, Nokia and Motorola mobile sets. If 75 liked Nokia or Motorola and 50 liked Motorola then find the number of students who liked Sony or Motorola but not Nokia.

Here we have given, n(N or M) = n(NUM) =75 or, z + y + x + x + 7 + 8 = 75 or, z + 2x + y = 50 .......................i) Again, n(M) = 50 or, x + y + z + 7 = 50 or, x + y + z .....

8. The historical peoples movement of 2062/063 became successful only by the unified effort of the political parties. Justify.

Nepal has experienced different movements. Some were limited to an ethnic group while others were limited to the whole nation people. Peoples' movement 2046, 2062/063, maoist insurgency, madhes movement are some examples. The succes and .....

9. Write an essay about "The book I enjoyed most".

While writing about your favorite book or the book you enjoyed most, you can consider the following things: 1. Give general information about the book/ Include what readers ought to know about the book. 2. Short plot --- Give a brief .....

10. Write an essay about "homework advantages and disadvantages."

What do you think of homework when it comes to your .....

11. Write an essay about "Science is a good servant but a bad master".

Science is a bad master. Technologies are being misused. People are taking the advantages of technologies for an inhuman act as well. For example; the atomic energy is being used for destructive purposes. Due to modern scientific gadgets, .....

12. Which of the following are sets? Justify your answer.
a) The collection of all the days in a week beginning with the letter 'T'.
b) The collection of all difficult questions in the chapter on sets.
c) The collection of girls in your class.
d) The collection of all rivers in india.
e) The collection of all active teachers in the school.
f) The collection of all integers more than 3.
g) The collection of all beautiful flowers in the park.

If,
A = {3, 5, 7, 9}
B = {2, 4, 6, 8, 10}
C = {12, 14, 18, 20, 24}
D = {21, 26, 31, 36}
(a) State whether true or false.
i) 13 ∈ C
ii) 6 ∉ A
iii) 9 ∉ A
iv) 24 ∈ C
v) 31 ∈ D
vi) 36 ∉ D
vii) 20 ∉ C
viii) 9 ∈ A

(b) Fill in the blanks.
i) 3 ∈ ___
ii) 4 ___ B
iii) 26 ___ C
iv) 8 ∈ ___
v) 5 ___ A
vi) 6 ___ C
vii) 21 ___ D
viii) 18 ___ B

But in (b) , can you say which problems are difficult and which are easy? Some question you feel difficult, it may be easy for others. So it can not define proparly. Thats why, this is not a .....

13. Ritic sold two cameras for Rs. 24,000 each. On one camera, he gained 20% and on the other, he lost 20%. Find the gain or loss percentage in the whole transaction.

Here , for the frist camera, SP = CP + gain %v of CP or, Rs.24000 = CP + 20 /100 X CP or, CP = 2400 x 120 / 100= 2880 For second camera, SP = CP - loos %v of CP or, Rs.24000 = CP - 20 /100 X CP or, CP = 2400 x 80 .....

14. A shopkeeper has got 20% profit to sell a bicycle to his labelled price. But he will gain only Rs.140 to give at 5% discount. What was the cost price of that bicycle?

Let the Marked Price(MP) = Rs. x. 1st condition: Selling at MP, So, SP1 = MP And, P% = 20%. So, CP = SP*100/( 100 + P%) = x(100)/(120) = 5x/6. Therefore, CP = Rs. 5x/6. Again, 2nd condition: D% = 5% And, Profit(P) = Rs. 140 So, SP .....

15. The sum of three numbers in AP is 12 and the sum of whose square is 56. Find the numbers.

(a - d)2 + a2 + ( a + d)2 = 66 or, a2 - 2ad + d2 + a2 + a2 + 2ad + d2 = 66 or, 3 x 16 + 2d2= 66 or, 2d2 = 66 - 48 or, 2d2 = 18 or, d = 3 or, - .....

16. In the Venn diagram, N, K and G denote the readers of the Nayapatrika, the Kantipur and the Gorkhapatra respectively. If 22 read the Kantipur, 36 read the Nayapatrika or the Kantipur and all the people read at least one of these, find the readers who read:
i) Exactly only one magazine and
ii) The Nayapatrika or the Kamtipur but not Gorkhapatra.

Here, n(K) = 22 so, 7 + 8 + 4 + x = 22 or, x = 3 Again, n(N) = 36 or, x + y + 7 + 5 = 36 or, y = 36 - 12 - 3 = .....

17. What are the seven fundamental units included in the SI system?

In S.I. system, length is measure in meter (m) Mass is measure in kilogram(kg) Time in second (s) Current in ampere (A) Tempareture in kelvin (K) Amount of substances in mole Luminous intensity in candela These are .....

18. What is SI system? Why was it introduced?

There were different local (and standard as well) units used in the world for measurement. Due to which, there was a difficulty for a global understanding about the units. 1 Tola gold measured in our country, when sent to the US, would .....

19. What are the general systems of units?

.....

20. Differentiate between fundamental unit and derived unit.

1. Fundamental units are single units while derived units are composed of two or more units. e.g. m, s, kg (fundamental); m/s, kg/m3, m2, m3 (derived). 2. Fundamental units are the units of directly measured quantities while derived units .....

21. What is unit? Mention its types.

Unit is the standard reference used for comparision during the measurement of a physical quantity. For example - metre, centimetre, gram, kilogram, second, kelvin etc. There are two types of units, they are: fundamental unit and .....

22. What is acceleration? Do the terms 'acceleration' and 'retardation' have the same meaning?

The rate of change of velocity is called acceleration. Its SI unit is m/s2 . Mathematically, Acceleration (a) = final velocity (v) - initial velocity (u) .....

23. Car 'A' is moving with a velocity of 36 km/hr due east and car 'B" is moving with a velocity of 72 km/hr due west. What is the relative velocity of car 'A' with respect to car 'B'? What will be the distance between them after 5 seconds if they start to move from the same point?

Here, Velocity of car A (VA) = 36 km/hr = 36 x 1000 m/s = 10 m/s (due east). .....

24. What is relative velocity? How can we calculate it?

Relative velocity is the velocity of a body compared with the velocity of another body. If two bodies are moving in the same direction, the relative velocity is calculated by subtracting their velocities (i.e. VAB = VB - VA). If two .....

25. A motorbike covers 2.4 km in 5 minutes. What is the average velocity of the moterbike?

Total displacement (d) = 2.4 km = 2400 m Total time taken (t) = 5 mins = 300 seconds Therefore, average velocity = d/t = 2400 m / 300 s .....

26. OverView video ले के सहयेता गर्छ।

.....

27. Convert:
a) 2500 g into kg b) 3 hr into sec

Similarly, try to solve the second question by yourself. If you have any problem sloving, please let us .....

28. What is this Overview Videos for?

.....

29. What is meant by 1 second time? How can we measure that amount of time?

one part of total 86400 parts of a solar day is known as 1 second time. We can measure the amount of time by the use of either a pendulum watch or a digital .....

30. What is weight? How is it different from mass?

Answer: Weight of a body is the force with which the body is attracted by the earth. It is the gravity of the earth acting on the body. Weight is different from mass in the following aspects: 1. Mass of a body is the amount of matter .....

31. Why is mass called fundamental quantity?

Mass is measured directly using a beam balance. It does not depend upon any other quantity and needs no calculation for measurement. So, it is a fundamental .....

32. What is physical quantity? Mention its types.

Answer: The quantity which can be measured directly or indirectly is called physical quantity. Mass, length, time, temperature, velocity, density, etc. are the examples of physical quantities. Explanation: There are two types of .....

33. Find the co-ordinates of the foot of the perpendicular from the point (4, 4) on the line x + y = 4.

Given line is x+y = 4.....(i) Let the foot of ⊥ of the point (4,4) on (i) be D(x1,y1) Slope of the line x+y= 4 is m1=−1 ⇒Slope of the ⊥ is 1 i.e.,m2=1 (slope of .....

34. A car starts from rest and gains a velocity of 20 m/s in 10 seconds. Calculate its acceleration and the distance covered by it in this time.

To calculate the distance covered (s), use the formula, s = (u + v) x t . .....

35. Sound of a dogs bell is fainter than a temple's bell, why?

That is why, the sound of a dog's bell is fainter than the sound of a temple's .....

36. What is acceleration? Calculate the acceleration of a car which takes 5 seconds to change its velocity from 10 m/s to 20 m/s.

Here, Initial velocity of the car (u) = 10 m/s. Final velocity of the car (v) = 20 m/s. Time taken to change the velocity (t) = 5 s. Acceleration of the car (a) = ? We have, Acceleration (a) = v - u .....

37. What is velocity? Differentiate between uniform and variable velocity.

There is no acceleration in uniform velocity, but there is some acceleration in variable .....

38. Differentiate between scalar and vector quantity?

1. Vector quantity has both magnitude and direction but scalar quantity has no direction (only the magnitude). 2. Vector quantity may have positive or negative value while scalar quantity has only the positive value. 3. Mathematical .....

39. What is distance and displacement?

Distance (covered) is the length of actual path travelled by a body. Displacement is the shortest distance between the initial and the final points. In other words, it is the distance covered by a body in a fixed direction (in a .....

40. What is friction? How can we reduce it?

Friction is the force developped between any two surfaces in contact, that opposes the motion of a body over another. We can reduce friction by the following ways: 1. By polishing the surfaces to make them smooth. 2. By using .....

41. What is gravity? Define gravitational force.

Gravity is the force with which the earth (or any other heavenly body) attracts a body lying inside its gravitational field. Gravitational force is the force of attraction between any two bodies in the .....

42. Study the diagram given below and find the volume of the ball.

You can calculate the volume of the ball by subtracting the volume of water from the volume of water with ball. That is, Vb = V(w+b) - Vw Can you find the required answer .....

43. What is area? If the length of a book is 30 cm and its breadth is 20 cm, calculate its area.

Here, Length of the book (l) = 30 cm. Breadth of the book (b) = 20 cm. Area of the book (A) = ? We have, Area (A) = length (l) x breadth (b) .....

44. चित्रकलाको बिकासमा ग्रन्थचित्रको कस्तो भूमिका रहेको छ ?

विद्यार्थीलाई पढाउन, मनोभावनालाई खुलस्त पार्न र सिकाइका लागि वस्तुनिष्ठ बनाउन चित्रकलाको .....

45. विवेचनात्मक उत्तर दिनुहोस् ।
' नेपाल ' कवितामा कविले नेपालको प्राकृतिक सुन्दरताको वर्णन कसरी गरेका छ्न ?

नेपाल कविताका लेखक सिद्धिचरण श्रेष्ठ हुन् । उनको जन्म मृत्यु (१९६९–२०४७) मा भएको थियो । यो .....

46. विवेचनात्मक उत्तर दिनुहोस् ।
' मित्रता ' कथामा द्रोणले द्रुपदको घमण्ड तोडेर मित्रको परिचय कसरी दिए ?

तपाईंहरुलाई पक्कै पनि थाहा होला द्रुपद र द्रोण बाल्यकालका घनिष्ठ मित्र थिए भन्ने कुरा , तर पछी .....

47. विवेचनात्मक उत्तर दिनुहोस् ।
भुगोलविद हर्क गुरुङ कस्ता स्वभावका व्यक्ती थिए ?

डा. हर्क गुरुङ, संरक्षण क्षेत्रमा मात्र होइन, देश विदेशमा परिचित नाम हो । ७ वर्षअघि आजैको दिन .....

48. In the adjoining figure, ∠PQR = 90° and QS ⊥ PR. Prove that PQ² + RS² = QR² + PS².

.....

49. If x be the length of a side of an equilateral triangle, show that the altitude of the triangle is x32.

Let us take a triangle as in figure, Let side of this triangle be x, then AD = x /2 And AD is perpendicular to AB, i.e; Triangle ADB is a right angle triangle. So we can use the Pythagoras theorem AC2 = BD2 + AD2 .....

50. In the figure alongside, ABCD is a trapezium. M and N are the mid-points of AD and BC respectively. Prove that AQ = QC and BP = PD.

Here we have given, ABCD is trapazium with in which, AB // CD. M is mid -point of AD and N is mid - point of AC. We have to prove , AQ = QC and BP = PD , i.e; Q is mid - point of AC and P is mid point of .....