Question

A particle is going with constant speed along a uniform helical and spiral path separately as shown in figure then

[Assume that the vertical acceleration of the particle is negligible in case (a)]

• A. The velocity of the particle is constant in both cases
• B. The magnitude of acceleration of the particle is constant in both cases
• C. The magnitude of acceleration is constant in (a) and decreasing in (b)
• D. The magnitude of acceleration is decreasing continuously in both the cases

Answer 1

The correct option is C The magnitude of acceleration is constant in (a) and decreasing in (b)

Since acceleration, $a=\frac{v^2}{r}$

and velocity is uniform and radius is constant in figure $\left(a\right)$

Therefore, acceleration is constant.

But in figure $\left(b\right)$, although the velocity is constant but the radius is increasing.

Therefore, acceleration is decreasing.