Why are symbols used in circuit diagrams

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Calculate a pendulums frequency of oscillation (in hz) if the pendulum completes one cycle in 0.5s.

6. an article, which costs rs. 850 is sold at a profit of 6%.what is the selling price ? -a) rs.900 b) rs. 901 c) rs. 890 d) rs. 905