Last seen: Jan 25, 2021
(a) Suma is doing work. She is applying force to move horizontally. (b) Donkey is not doing any work. Here, the displacement and the force are at 90...
Average power = The concept of average power is useful when the power of an agent varies with time and it does work at different rates during diffe...
Given, Energy consumed = 1000 J Time = 10 s Power = = = = 100 W (∵ 1 Js-1 = 1 W)
Power of an object is said to be 1 W if it does 1 joule of work in 1 s, i.e., 1 watt (W) = In other words, we can say that power is 1 W when the ...
The rate of doing work is called power. Thus, Power (P) = or P =
K.E. of an object = = 25 J K.E. of the object with velocity double of initial = = = 4 x 25 J = 100 J K.E. of the object with velocity triple ...
Kinetic energy of an object, K.E. = 1/2 where m = mass of the object and v = uniform velocity of the object.
Kinetic energy of an object is the energy possessed by it due to its motion. In fact, kinetic energy of an object moving with a certain velocity is eq...
Here, F = 140 N, s = 15 m. Work done in ploughing the field, W = F × s = (140 N) × (15 cm) = 2100 J
The amount of work done when a force of 1 N moves a body through a distance of 1 m in the direction of the force is called 1 joule.
If F is the constant force acting in the direction of displacement s, then work done by the force, W = F × s = Fs.
Work is done by a force on an object if a force acts on the object and the object is displaced from its original position.
Force, F = 7 N Displacement, s = 8 m Then, work done = 7N x 8 m = 56 Nm = 56 J
(d) Tarun wanted to measure the amount of water displaced by each ball when dipped in water. (b) The principle used is ‘Archimedes’ principle’. (c...
(a) The high heel shoes would exert lot of pressure on the loose sand of beach and will sink more in the soil as compared to flat shoes. Hence large a...
(a) Lactometer is a device that measures the purity of milk. (b) The principle of lactometer is ‘Archimedes’ principle’. It states that when a body...
Note the elongation of the string or the reading on the spring balance due to the weight of the stone. Now, slowly dip the stone in the water in a co...
The iron nail sinks as the density of nail is more and the downward force exerted on nail is more than the buoyant force. The cost floats as the densi...
The iron nail sinks as the density of nail is more and the downward force exerted on nail is more than the buoyant force. 2s.png
Yes, the bottle is attracted downwards by the earth’s gravitational force. On pushing the bottle with force in the water it does not remain there but ...