A particle moves along x-axis such that its position veries with time as `x=50t-5t^2`. Select the correct alternative (s).

Options

A. There must be a fourth force acting on the particle
B. There may be a fourth force acting on the particle
C. There must be only given three forces acting on the particle
D. There may be only three given forces acting on the particle

Answer

bd

Explanation

We find that resultant is along ‘2F’ (`240^(@)` with +ve x-axis). If the particle is moving along `60^(@)` with +ve x-axis there are two possibilities. (i) There is a fourth force (ii) The particle was given an initial velocity in this direction