if there is gravity, does centre of mass and centre of gravity always coincide? if no, why and give example?

A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mm

at the free end, where a small mass of 2 g is positioned. determine

(i) The velocity of the end when passing through the zero position

(ii) The acceleration at maximum displacement

(iii) The maximum kinetic energy of the mass

An object of mass m = 0.25 kg oscillates in a fluid at the end of a vertical spring of spring

constant kH = 85 N/m, see Fig.1. The effect of the fluid resistance is governed by the

damping constant b = 0.07kg/s.

(i) Find the period of the damped oscillation.

(ii) By what percentage does the amplitude of the oscillation decrease in each cycle? 

If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0

A particle is traveling in a circle of radius R =2.5m and with an angular velocity of 10 rad/s. What is the centripetal acceleration of the particle? The particle begins to slow down with an angular acceleration of -1 rad/s². After 5 seconds, what is the centripetal acceleration and the tangential acceleration fo the particle?

If the acceleration of block A is 5 m/s^2

Find the acceleration of block B