[GS] [Physics] Important Facts In Science

[GS] [Physics]

Important Facts In Science

• Light year is the unit of distance. the distance that light travels in one year, about 9.4607×10¹² Kilometres.

• The velocity of planet changes at the time of revolving the sun. When the planet closes the sun then its velocity is maximum and vice – versa.

• The unit of work and energy is Joule. The SI derived unit used to measure energy or work. One joule is equal to the energy used to accelerate a body with a mass of one kilogram using one newton of force over a distance of one meter. One joule is also equivalent to one watt-second.

• The Pisa Minerate is slanting but it does not fall because the line passes through its centroid and its base also.

• At first Ultrasonic waves are produced with a whistle by Galtan.

• Centroid is that point where the whole weight of the thing acts.

• The sky seems blue due to scattering of light.

• The total mechanical energy of the falling body remains constant.

• The mass of a thing is always constant while its weight is different at different places.

• On earth the weight of the body is minimum at the mediterian line and the maximum at the poles.

• In taking one round of sun by the earth, total work is zero.

• To measure the humidity in air, Hygrometer is used.

• Sound waves cannot travel in vacuum.

• The time taken in one vibration is said to be time period.

• If a thing is dipped into a liquid then the decrement in its weight is equal to the weight of the displaced water.

• At the time of climbing the mountains, the person bends forward so that the line of the centre of gravity is also to be passed his feet.

• The product of mass and velocity is said to be momentum. Momentum is product of the mass of a particle and its velocity. Momentum is a vector quantity; i.e., it has both magnitude and direction. Isaac Newton’s second law of motion states that the time rate of change of momentum is equal to the force acting on the particle.

• When a battalion of army crosses a bridge then the soldiers are advised not to proceed as a unit because the bridge may be collapsed due to resonance.

• The horse pulls the cart forward as the third law of newton.

• Work is equal to the product of force and displacement.

• The food gets cooked very delay on mountains as the atmospheric pressure decreases and the boiling point of water also decreases.

• A clock with hand has potential energy.

• The number of vibrations in one second is said to be frequency.

• At the same depth, the pressure of liquid remains same in every direction.

• In candle, the chemical energy converts into light and heat energy.

• In a tight rubber string, elastic potential energy exists there.

• We can hear those waves the frequency of which is between of 20 Hertz to 20000 Hertz.

• If the frequency of the waves is below 20 Hertz then the waves are said to be infrasonic waves.

• If the frequency of the waves is above 20000 Hertz then the waves are said to be ultrasonic waves.

• Diamond shines due to total internal reflection.

• The gravity at the moon is 1/6^th than that of the earth.

• The escape velocity on the earth is 11.2 km/sec.

• The value of gravity is zero at the centre of the earth.

• Universal gravitational law was given by Newton.

• In railway line, there is some gap between the lines because in summer these lines expand.