(b) The distance travelled by light in one year
A light-year is the distance light travels in one year. It is a unit of astronomical distance, and is equal to 9.461 trillion kilometers. Light travels through interstellar space at 186,000 miles (300,000 kilometers) per second, and 5.88 trillion miles (9.46 trillion kilometers) per year.
A light-year is a measure of distance, not time. It is the total distance that a beam of light, moving in a straight line, travels in one year.
The International Astronomical Union defines a light-year is the distance light travels in 365.25 days. A light-year is a distance that light travels in a vacuum in one Julian year (365.25 days).
The nearest star to us is about 4.3 light-years away.
The Milky Way galaxy is about 150,000 light-years across, and the nearest large galaxy, Andromeda, is 2.3 million light-years away.

(c) Force of the wind
Anemometer, a device for measuring the speed of airflow in the atmosphere, in wind tunnels, and in other gas-flow applications. Most widely used for wind-speed measurements is the revolving cup electric anemometer, in which the revolving cups drive an electric generator. The output of the generator operates an electric meter that is calibrated in wind speed.
This device is especially suited for the measurement of low airspeeds. (The useful range of this device is approximately from 5 to 100 knots)

(c) Depth of sea
Fathometer’ is used to measure Ocean Depth. It is an instrument used for measuring the depth of water by the time required for a sound wave to travel from surface to bottom and for its echo to be returned. It can also be used to measure the rise and fall of the tides in offshore localities.

(c) Displacement
A vector quantity is a physical quantity that has both magnitude and direction. Vector quantities are represented by mathematical objects called vectors, which are represented geometrically by arrows. Displacement is the difference between an object’s final and initial position. It is represented as an arrow that points from the starting position to the final position.

(a)
If the gravitational force on earth disappears, then there would be no acceleration acting on a body downwards, hence, there will be no force acting on the body due to gravity, hence, the weight of the body will become zero.
If the gravitational force of the earth suddenly disappears, then weight of the body is zero because gravity of earth becomes zero.
w = mg ⇒ w = m × 0 = 0