General Physics

The hydraulic system works on the principle of Pascal's law which says that the pressure in an enclosed fluid is uniform in all the directions.

Alcohol is more volatile than water because it boiling point is lower than water.

Manometers are precision instruments that are used to measure pressure, which is the force exerted by a gas or liquid per unit surface area owing to the effects of the weight of that gas or liquid from gravity.

Weightlessness in space is caused by the simple physical factors that cause the limitation of gravity. While on Earth, external forces are pushing or pulling on a person’s body, however when a spacecraft enters orbit, the people and objects aboard the craft enter a state of free fall.

Deta Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more friction slowing him down because air resistance works against the very large surface area of the parachute.ils

Long distance propagation of radio waves depends on an invisible layer of charged particles, which envelops the Earth. This layer of charged particles known as the ionosphere has been in existence for millions of years.

The answer is related to the conservation of angular momentum. The person on the rotating table will maintain approximately the same angular momentum during the spin. If he moves his arms in, it will reduce the rotational inertia by reducing the distance of the mass of her arms and hands from the axis of rotation. In order to maintain the same angular momentum, angular rotation is increased.

An orbiting satellite is a projectile in the sense that the only force acting upon an orbiting satellite is the force of gravity. A satellite is acted upon by the force of gravity and this force does accelerate it towards the Earth. In the absence of gravity a satellite would move in a straight line path tangent to the Earth.

Gasoline or petrol is a transparent, petroleumderived liquid that is used primarily as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives.

The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities.

Radio is the transmission of signals through free space by electromagnetic radiation of a frequency significantly below that of visible light, in the radio frequency range, from about 30 kHz to 300 GHz. These waves are called radio waves. Experiments were undertaken by Thomas Edison and his employees of Menlo Park.

As, the earth is not a perfect sphere, the gravity keeps on changing as we move from one place to another. But it is maximum at the place where it is nearer to the centre. So,Earth's gravity is the maximum at the poles because the Earth is kind of an ellipse (not a perfect sphere). And the equator is further away from the centre of mass of the Earth than at the poles.
So, as we go from equator to poles, the value of g increases.

The speed of an object in a particular direction is called velocity.

Details

Initial speed = u = 18 km/hr = 5 m/s
Final speed = v = 72 km/hr = 20 m/s
acceleration a = (v-u)/t = (20 - 5)/5 = 3 m/s².