Mechanics and Properties of Matter
The centripetal force required for a car to bicyle to go round a circular curve depends on
  • The angle of elevation of the curved track
  • Speed of the vehicle only
  • The radius of curvature of the path only
  • Speed and the radius of curvature of the curve
Explanation: Centripetal force (Fc) is required to keep a vehicle moving in a circular path and is given by the formula: Fc=mv2/r where: • m is the mass of the vehicle, • v is the speed of the vehicle, • r is the radius of curvature. From the equation, we can see that centripetal force depends on both the speed of the vehicle (v) and the radius of curvature (r).
The angle of projection for a projectile to cover maximum range is
  • 0°
  • 30°
  • 45°
  • 60°
  • 0°
  • 30°
  • 45°
  • 60°
Explanation:
The geocentric theory is given by
  • Aristotle
  • Newton
  • Prout
  • Ptolemy
Explanation: The geocentric theory, which states that Earth is the center of the universe, was proposed by Claudius Ptolemy.
A rocket is not a projectile until its
  • Energy is wasted
  • Energy is saved
  • Propellant fuel is not burnt
  • Propellant fuel is burnt
Explanation: A rocket is not a projectile until its propellant fuel is completely burnt because, before that, it is still being propelled by thrust. Once the fuel is exhausted, it follows a projectile motion under gravity.
The molecular range is of the order of
  • 10⁻⁸ cm
  • 10-8 m
  • 10-6 cm
  • 10-6 m
Explanation: The molecular range refers to the distance up to which molecular forces act. It is typically in the range of 10⁻⁸ cm (or 10⁻¹⁰ m), which is approximately the size of molecules.
The centripetal force around the circular path depends upon
  • Energy