A body moving with SHM has an amplitude of 10cm an a frequency of 100Hz. Find i. the period of oscillation, ii. the acceleration at the maximum displacement, iii. the velocity at the centre of motion.

Ahuge (essentially infinite) horizontal nonconducting sheet 10.0 cm thick has charge uniformly spread over both faces. the upper face carries +95.0 nc/m2 while the lower face carries -25.0 nc/ m2. what is the magnitude of the electric field at a point within the sheet 2.00 cm below the upper face? (ε0 = 8.85 × 10-12 c2/n · m2)