Why eccentric resistance training exercise should be avoided in elderly

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?