Noel is studying momentum at a bowling alley. He rolls a bowling ball down a lane to hit a bowling pin. The lane is smooth and polished to greatly reduce friction. Noel measures the velocity of the ball before and after it hits the pin. The ball is sliding before and after it hits the pin, it
carries the pin with it, as shown in the diagram.
Before
8 m/sec 0 m/sec
After
6.5m/sec
6.5 kg 1.5 kg

Noel claims that the bowling ball-and-pin system demonstrates conservation of momentum.

Which equation represents the interaction in the diagram?

A: (6.5 kg)(8 m/sec) + (1.5 kg (0 m/sec) = (6.5 kg)(6.5 m/sec) + (1.5 kg)(6.5 m/sec)

B: (8 m/sec (0 m/sec) = (6.5 m/sec)(0 m/sec)

c: (8 kgm/sec) - (15 kgm/sec) = (6.5 kgm/sec) + (0 kgm/sec)

D: (1.5 kg)(6.5 m/sec)=(1.5kg) (6.5 m/sec)

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.