Assignments and Notice

  Energy: The Power to Do Work Energy is the ability to do work. Everything around us needs energy to move, grow, change, or function. We get energy mainly from the food we eat, while machines and vehicles may get energy from fuels or electricity. There are different forms of energy. Kinetic energy is the energy possessed by a moving object. For example, a moving bicycle has kinetic energy. Potential energy is stored energy. A stone kept at a height and water stored in a dam have potential energy. Other important forms include heat, light, sound, electrical, and chemical energy . Energy can change from one form to another. For example, when we switch on an electric bulb, electrical energy changes mainly into light and heat energy. In a hydroelectric power station, the energy of falling water is converted into electrical energy. Similarly, when we eat food and run, chemical energy stored in food changes into kinetic energy and heat energy. The law of conservation of energy...

  Questions Number and Operations: Simplify: 3 4 + 5 6 − 1 3 \frac{3}{4}+\frac{5}{6}-\frac{1}{3} Percentage: A school has 800 students. If 35% of them are girls, how many boys are there? Ratio: The ratio of boys to girls in a class is 3:2 . If there are 40 students in the class, how many boys and girls are there? Algebra: Solve for x x : 3 x − 7 = 2 x + 9 3x-7=2x+9 Algebraic Expression: Factorize: x 2 + 7 x + 12 x^2+7x+12 Profit and Loss: A shopkeeper buys a school bag for Rs. 800 and sells it for Rs. 920 . Find the profit percentage . Geometry: The length of a rectangular garden is 18 m and its breadth is 12 m . Find: a) its area b) its perimeter Speed, Distance and Time: A bus travels at an average speed of 45 km/h . How far will it travel in 2 hours 40 minutes ? Statistics: The marks obtained by five students in a mathematics test are: 12, 18, 15, 20, and 10 . Find the mean mark . Logical Mathematical Reasoning: A number is multiplied...

Force and Motion Force is a push or pull that can change the state of rest or motion of an object. The SI unit of force is newton (N) . According to Newton’s second law of motion, the force acting on an object is equal to the product of its mass and acceleration: F = m a F = ma where F F is force, m m is mass, and a a is acceleration. Motion describes the change in position of an object with time. The distance travelled by an object is the total length of its path, while displacement is the shortest distance between its initial and final positions in a particular direction. Speed is the distance travelled per unit time, whereas velocity is displacement per unit time. Acceleration is the rate of change of velocity with time. When an object moves with uniform acceleration, the following equations of motion can be used: v = u + a t v = u + at s = u t + 1 2 a t 2 s = ut + \frac{1}{2}at^2 v 2 = u 2 + 2 a s v^2 = u^2 + 2as Here, u u is initial velocity, v v is final velocity,...