Which of the following statements is ALWAYS true about a particle moving along a line?

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

Which of the following statements is ALWAYS true about a particle moving along a line? (a) The particle’s speed increases exactly when

v(t)

and

a(t)

have opposite signs. (b) The particle’s speed increases whenever

a(t) > 0

.},{ (c) The particle’s speed increases exactly when

v(t)

and

a(t)

have the same sign. (d) The particle’s speed increases only when

v(t) > 0

and

a(t) > 0