Answer:
6 m/s
Explanation:
12m / 2s = 6 m/s
Hope that's the answer you seek.
The weight of the meterstick is:

and this weight is applied at the center of mass of the meterstick, so at x=0.50 m, therefore at a distance

from the pivot.
The torque generated by the weight of the meterstick around the pivot is:

To keep the system in equilibrium, the mass of 0.50 kg must generate an equal torque with opposite direction of rotation, so it must be located at a distance d2 somewhere between x=0 and x=0.40 m. The magnitude of the torque should be the same, 0.20 Nm, and so we have:

from which we find the value of d2:

So, the mass should be put at x=-0.04 m from the pivot, therefore at the x=36 cm mark.
Answer:
q₃ = -4.81 nC
Explanation:
We can use the Gauss Law here:
∅ = q/∈₀
where,
∅ = Net Flux = - 216 N.m²/C
q = total charge enclosed inside sphere = ?
∈₀ = permittivity of free space = 8.85 x 10⁻¹² C/N.m²
Therefore,
- 216 N.m²/C = q / 8.85 x 10⁻¹² C²/N.m²
q = (-216 N.m²/C)(8.85 x 10⁻¹² C²/N.m²)
q = - 1.91 nC
So, the total charge will be sum of all three charges:
q = q₁ + q₂ + q₃
- 1.91 nC = 1.74 nC + 1.16 nC + q₃
q₃ = - 1.91 nC - 1.74 nC - 1.16 nC
<u>q₃ = -4.81 nC</u>
The first choices are correct, because the second choices could happen by things other than light.