Question

A sphere is rotating about a diameter,
(a) The particles on the surface of the sphere do not have any linear acceleration.
(b) The particles on the diameter mentioned above do not have any linear acceleration.
(c) different particles on the surface have different angular speeds.
(d) All the particles on the surface have same linear speed.

Answer 1

Answer ⇒ Option (b) .

''The particles on the diameter mentioned above do not have any linear acceleration''.

Explanation ⇒ We know that the particles on the surface of the sphere revolve in concentric circles.

Therefore, at least they must have the centripetal accelerations. ∴ (a) is not true.

Different particles on the surface take equal time to complete a revolution, hence they have equal angular speeds. ∴ (c) is not true.

The linear speed v = ɷr. That means the particles at different r will have different linear speed. ∴ (d) is not true.

Since for the particles on the diameter r = 0. So, v = 0. Since v is not changing so linear acceleration is zero. ∴ is correct.

Hence, Option (b). is Correct.

Hope it helps.

Answer 2

HEY!!

___________________________

✔✔(b) is the correct option.

✴Explanation:-

▶Linear acceleration of a rotating particle is given as:-

▶a⃗ =r⃗ ×α⃗ 

▶The sphere is rotating about a diameter.

▶Therefore, the position vector of the particles on the diameter is zero.

▶▶That's why the linear acceleration of the particle is zero.