Which one of the following statements is not true ?
The gravitational force of earth acting on a body of mass 1 kg is 9.8 newton
The force acting on an object of mass 5 kg moving with a uniform velocity of 10 m/s on a frictionless surface is zero
The SI unit of weight is kg
The momentum of a man having mass 100 kg walking with a uniform velocity of 2 m/s is 200 newton second
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CAPF – 2016
Statement B is correct: If an object moves with uniform velocity, its acceleration is zero (a=0). According to Newton’s second law, the net force acting on the object is F = ma. If a=0, then F=0. On a frictionless surface, there are no opposing forces like friction.
Statement D is correct: Momentum (p) is calculated as mass (m) times velocity (v). p = 100 kg * 2 m/s = 200 kg⋅m/s. The unit kg⋅m/s is equivalent to Newton-second (N⋅s), as 1 N = 1 kg⋅m/s². So, the momentum is 200 N⋅s.