An electrostatic system consists of two earthed concentric spherical shells of very small thickness and of radii "a" and "2a" respectively. The region a ≤ r ≤ 2a bears a charge distribution:

\gamma_o = constant

1. Determine a value for \gamma_o if the total charge is Q.

2. Show that the potential is:


3. Sketch the directed electric field configuration of the system.

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

What is friction? how does it affect the motion of an object?

(8%) problem 12. a bowling ball of mass mb 3 kg 's rolled down the lane with a velocity ofy-2/ m s lt strikes a single remaining pin mp 0.93 kg head on. after the collision the bowling ball has a velocity (in the same direction) of v2 1.1 m/s. = ▲ 33% part (a) write an expression for the velocity of pin in the horizontal direction after the impact, im ,, 33% part (b) what is the pins speed in ms? 33% part (c) assuming the coefficient of friction s μ,-0.1. how far in meters could the pin slide before stopping if it doesn't topple?