Copper, because it has the lowest specific electrical resistance.
specific electrical resistance aka volume resistivity is a fundamental property of a material that quantifies how strongly that material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current.
Answer:
The average acceleration of the ball during the collision with the wall is 
Explanation:
<u>Known Data</u>
We will asume initial speed has a negative direction,
, final speed has a positive direction,
,
and mass
.
<u>Initial momentum</u>

<u>final momentum</u>

<u>Impulse</u>

<u>Average Force</u>

<u>Average acceleration</u>
, so
.
Therefore, 
If an object's velocity is steadily increasing it means that the acceleration is constant at a certain value.
Choice A shows an acceleration of zero which would only be true if the object was not moving or if its velocity was not changing.
Choice B gives us a graph showing acceleration increasing over time and is therefore incorrect.
Choice C is correct because the acceleration is constant. Steadily increasing tells us that the acceleration is fixed at a certain value.
Choice D is incorrect an represents a constant negative acceleration. This would be the case if the object was steadily decreasing in velocity.
Answer:
Explanation:
Let the charge particle have charge equal to +q .
force due to electric field will be along the field that is along y - axis . To balance it force by magnetic force must be along - y axis. ( negative of y axis )
force due to magnetic field = q ( v x B ) , v is velocity and B is magnetic field.
F = q ( v i x B k ) , ( velocity is along x direction and magnetic field is along z axis. )
= (Bqv) - j
= - Bqv j
The force will be along - ve y - direction .
If we take charge as negative or - q
force due to electric field will be along - y axis .
magnetic force = F = -q ( v i x B k )
= + Bqv j
magnetic force will be along + y axis
So it is difficult to find out the nature of charge on the particle from this experiment.