A hollow metal sphere has 6 cmcm and 11 cmcm inner and outer radii, respectively. The surface charge density on the inside surface is −150nC/m2. The surface charge density on the exterior surface is +150nC/m2. What is the strength of the electric field at point 4 cm from the center?

If a tank filled with water contains a block and the height of the water above point a within the block is 0.8 meter, what is the pressure at point a?

Ahole in the ground in the shape of an inverted cone is 14 meters deep and has radius at the top of 11 meters. the cone is filled to the top with sawdust. the density of the sawdust depends upon the depth, x, following the formula ρ ( x ) = 2.5 + 1.2 e − 0.7 x kg/m3. find the total mass of sawdust in the conical hole.

What is the change in internal energy if 20 j of heat is released from a system and the system does 50 j of work on the surroundings? a. -70 j b. 30 j c. -30 j d. 70 j