# Lesson Archives

1. ## Solutions Chapter 4 – Laws of Motion

Page No 109: Question 5.1: Give the magnitude and direction of the net force acting on (a) a drop of rain falling down with a constant speed, (b) a cork of mass 10 g floating on water, (c) a kite skillfully held stationary in the sky, (d) a car moving with a constant velocity of […]
2. ## Solutions Chapter 3 – Motion in a Plane

Page No 85: Question 4.1: State, for each of the following physical quantities, if it is a scalar or a vector: volume, mass, speed, acceleration, density, number of moles, velocity, angular frequency, displacement, angular velocity. Answer: Scalar: Volume, mass, speed, density, number of moles, angular frequency Vector: Acceleration, velocity, displacement, angular velocity A scalar quantity […]
3. ## Solutions Chapter 2 – Motion in a Straight Line

Page No 55: Question 3.1: In which of the following examples of motion, can the body be considered approximately a point object: (a) a railway carriage moving without jerks between two stations. (b) a monkey sitting on top of a man cycling smoothly on a circular track. (c) a spinning cricket ball that turns sharply […]
4. ## Solutions Chapter 1 – Units and Measurements

Page No 35: Question 2.1: Fill in the blanks (a) The volume of a cube of side 1 cm is equal to…..m3 (b) The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to … (mm)2 (c) A vehicle moving with a speed of 18 km h–1covers….m in […]
5. ## Solutions Chapter 16 – Probability

Sum of probabilities Thus, the assignment is valid. (b) ω1 ω2 ω3 ω4 ω5 ω6 ω7 Here, each of the numbers p(ωi) is positive and less than 1. Sum of probabilities Thus, the assignment is valid. (c) ω1 ω2 ω3 ω4 ω5 ω6 ω7 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Here, each of the […]
6. ## Solutions Chapter 15 – Statistics

xi fi fi xi 10 4 40 40 160 30 24 720 20 480 50 28 1400 0 0 70 16 1120 20 320 90 8 720 40 320 80 4000 1280 Question 7: Find the mean deviation about the median for the data. xi 5 7 9 10 12 15 fi 8 6 2 […]
7. ## Solutions Chapter 14 – Mathematical Reasoning

Page No 324: Question 1: Which of the following sentences are statements? Give reasons for your answer. (i) There are 35 days in a month. (ii) Mathematics is difficult. (iii) The sum of 5 and 7 is greater than 10. (iv) The square of a number is an even number. (v) The sides of a […]
8. ## Solutions Chapter 13 – Limits and Derivatives

Page No 301: Question 1: Evaluate the Given limit: Answer: Question 2: Evaluate the Given limit: Answer: Question 3: Evaluate the Given limit: Answer: Question 4: Evaluate the Given limit: Answer: Question 5: Evaluate the Given limit: Answer: Question 6: Evaluate the Given limit: Answer: Put x + 1 = y so that y → […]
9. ## Solutions Chapter 12 – Introduction to Three Dimensional Geometry

Page No 271: Question 1: A point is on the x-axis. What are its y-coordinates and z-coordinates? Answer: If a point is on the x-axis, then its y-coordinates and z-coordinates are zero. Question 2: A point is in the XZ-plane. What can you say about its y-coordinate? Answer: If a point is in the XZ plane, then its y-coordinate is zero. Question 3: […]
10. ## Solutions Chapter 11 – Conic Sections

Page No 241: Question 1: Find the equation of the circle with centre (0, 2) and radius 2 Answer: The equation of a circle with centre (h, k) and radius r is given as (x­ – h)2 + (y ­– k)2 = r2 It is given that centre (h, k) = (0, 2) and radius (r) = 2. Therefore, the equation of the circle is (x – […]