Physics - NLM Question with Solution | TestHub

(A) The normal force equals weight only in special cases (horizontal surface, no other vertical forces, no vertical acceleration). On an incline N = mg cos$\theta$, and in an accelerating lift N differs from mg. Statement is incorrect.

(B) With constant acceleration, x = x_0 + v_0 t + (1/2) a t^2 - a parabola, not a straight line. Statement is incorrect.

$$\mathrm{x}={\mathrm{x}}_0+{\mathrm{v}}_0\mathrm{t}+\frac{1}{2}{\mathrm{at}}^2$$

(C) Zero velocity with non-zero acceleration is possible, e.g. a ball at the top of its vertical throw. Statement is correct.

(D) In free fall from rest, displacement s = (1/2) g t^2 - proportional to the square of the time, not to the time. Statement is incorrect.

Incorrect statements: (A), (B), (D).