Type of circuit does charge move in only one direction

A diode is a device that allows charges to move in only one direction. A diod consists of a PN-junction, with a semiconductor N-type region (with excess of electrons) bonded with a semiconductor P-type region (excess of holes). The region closed to the junction is called 'depletion zone', where electrons from the n-region recombine with holes from the p-region, and acts as an insulating zone. 

The n-region is then connected to the negative terminal of a battery, and the p-region to the positive terminal. This way, if the applied potential difference is strong enough, electrons will start to flow from the n-region (and then also from the depletion region) to the posititive terminal of the battery, while the holes will flow to the negative terminal, so a net current is flowing through the junction.

Vicceversa, if the two n-region is connected to the positive terminal and the p-region to the negative terminal, nothing happens through the junction, because both electrons and holes of the two regions are attracted by the "wrong side": in the n-region, electrons will flow to the negative terminal (so, not crossing the junction), and in the same way the holes of the p-region will flow to the positive terminal without crossing the junction, so no current is flowing through it.

    m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| =  √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| =  √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| =  14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s

Inelastic is the answer your looking for.