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A cube is pushed such that it slides on a horizontal surface. The friction can be increased by?

When mass of the block is decreased or the surface is polished, the friction is decreased. When another block of the same mass is placed on top... View Article

Calculate the pressure developed by a force of 50N acting on an area of 10m2.

Pressure is defined as the force per unit area, so here pressure developed would be simple force divided by the area i.e. 50/10 = 5 Pa... View Article

A circular disc is rotating with constant angular velocity ω about an axis that passes through the centre. A particle ‘P’ is kept at a distance of 2m from the centre and another particle ‘Q’ at a distance of 3m from the centre. Which of these will have higher centripetal acceleration?

If a particle goes in a circle with constant ω then it has a centripetal acceleration given by ω2R. since ω is constant for both particles. So... View Article

A fly was sitting on a block. A man draws a circle of area 2cm2, thus enclosing the fly. He then applies a force of 20N and kills it with a flat stick. Calculate the pressure on that area.

The area on which the pressure is calculated is 2 cm2, and the force applied by the stick is 20N in order to kill the fly sitting in that area.... View Article

If 10^20 electrons flow from the black body to the red body through the copper wire in 8 seconds, then find the current flowing between them.

We know that, q = ne Also, I = q/t Hence, I = ne/t = (1020 x 1.6 x 10-19) / 8 = 2 A... View Article

If a toy fan is connected across a battery for 2 minutes and we know that a charge transfer of 120 C takes place then find out the current in the circuit for that period of time.

Rate of flow of charge is called current.Hence, I=q/t =120 / (2 x 60) = 1 A... View Article

A body of dimensions (lxbxh) 2m x 3m x 4m is acted upon by a force of 50N on the top surface. Calculate the pressure due the force on that surface.

This body could be taken as a cuboid of dimensions 2m x 3m x 4m.So, 2m is the length, 3m is the breadth and 4m is the height of the body.... View Article

There are 2 school bags A & B. Bag A is provided with a broader strap while bag B is provided with a thinner strap. For the same load, a school boy likes bag A as he is comfortable with it, but with bag B, he develops a pain in his shoulders. Why?

Since, the pressure is the force per unit area therefore, in bag A as the straps are broader, the pressure developed would be less than B for the... View Article

A mosquito is making sound with its wings at an average rate of 500 vibrations per 10 seconds. The frequency of vibrations is

The number of oscillations per second= 500/10 = 50 Hz.... View Article

A chef while cooking cuts his hand with a sharp edged knife, but to his surprise his hand did not cut with a spoon even on the application of a greater force. Why it did cut from a knife for a smaller force.

Since the edge of the knife is very sharp, therefore the pressure developed is much larger for the same force in the case of knife than spoon.... View Article

What is Gravitational force?

The universal force of attraction acting between all matter is the gravitational force. It is by far the weakest known force in nature.... View Article

What part of human body is responsible for the voice production?

In humans, the sound of speech is produced by the Larynx or Vocal cord.... View Article

A little boy was playing tug of war with his elder brother; he tried everything but was unsuccessful in pulling the rope towards himself. Eventually, little boy lost the game because:- Statement1: Elder brother was capable of applying a greater force than his younger brother and hence the net force was in a direction to make him win. Statement2: An object moves in the direction of net force acting on it.

His elder brother was able to apply a larger force and hence the net force was in a direction which made the little boy to move towards his... View Article

A cannon ball (mass = 2 kg) is fired at a target of 500 meters away. The 400 kg cannon recoils by 50 cm. Assuming cannon ball moves with constant velocity, when will it hit the target? [Resistance offered by ground to cannon is 100 N]

Force by ground on the cannon = 100N.Work done by ground on the cannon = 100 x(0.5) = 50J.Applying conservation of energywork done by ground on... View Article

A bullet of mass 20 g travelling horizontally with a velocity of 100 m/s strikes a wooden block and comes to rest in 0.05 s. Calculate the magnitude of force in N exerted by the wooden block on the bullet.

Mass of bullet (m)= 20 g = 0.02 kgInitial velocity of bullet (u) =100 m/s ... View Article

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