Explanation: A rocket is not considered a projectile until its propellant fuel is burnt. Before the fuel is burned, it is still in the process of launching and accelerating, whereas once the fuel is burnt and the rocket is no longer generating thrust, it becomes a projectile, continuing its motion due to inertia and gravity.

Explanation: The geocentric theory, which suggests that Earth is at the center of the universe and all other celestial bodies revolve around it, was proposed by the ancient Greek astronomer Ptolemy.

Explanation: For a projectile to cover the maximum range, the angle of projection should be 45°. At this angle, the horizontal and vertical components of velocity are optimized, giving the projectile the farthest distance.

Explanation: The air resistance (or drag force) on a freely falling body depends on the shape, size, and speed of the object. A body with a larger surface area or irregular shape experiences more air resistance compared to a streamlined object. While pressure and density can also influence air resistance, the primary factor is the shape of the object.

Explanation: The centripetal force required for a vehicle to go around a circular curve depends on both the speed of the vehicle and the radius of the curve. The formula for centripetal force is: F = mv sq / r where: • m is the mass of the vehicle, • v is the speed of the vehicle, • r is the radius of the curvature. This shows that the force is directly proportional to the square of the speed and inversely proportional to the radius of the curve.

Explanation: A rocket is not considered a projectile until its propellant fuel is burnt. This is because the rocket's motion depends on the expulsion of exhaust gases, which generates thrust. The combustion of propellant fuels is what propels the rocket, making it a powered vehicle, unlike a projectile, which relies solely on initial velocity and gravity.