The electrons are already there. They are freely moving through the conductor.
Answer:
Volume strain is 0.02
Explanation:
Volume strain is defined as the change in volume to the original volume.
It is given that,
Initial volume of the plastic box is 2 m³
It is then submerged below the surface of a liquid and its volume decreases to 1.96 m³
We need to find the volume strain on the box. It is defined as the change in volume divided by the original volume. So,

So, the volume strain on the box is 0.02.
The cart comes to rest from 1.3 m/s in a matter of 0.30 s, so it undergoes an acceleration <em>a</em> of
<em>a</em> = (0 - 1.3 m/s) / (0.30 s)
<em>a</em> ≈ -4.33 m/s²
This acceleration is applied by a force of -65 N, i.e. a force of 65 N that opposes the cart's motion downhill. So the cart has a mass <em>m</em> such that
-65 N = <em>m</em> (-4.33 m/s²)
<em>m</em> = 15 kg