Answer:
3 m/s
Explanation:
Kinetic energy of a body is given by the formula 
. Let's replace everything we have and solve for what's left.
or 
The properties of the wave don't determine its speed. The properties of the medium do. You can FIND the speed by measuring the wave's frequency and wavelength.
Answer:
A
Explanation:
Because of the convectional currents
Answer: +2 e
Explanation: Net charge of a system is sum of charges on all the constituents of the system.
The system contains two spheres. Charge on one sphere is:
q₁ = +6 e
Charge on the second sphere is:
q₂ = -4 e
Net charge of the system is:
q = q₁ + q₂
q = +6 e + (-4 e) = + 2 e
Thus, the net charge of system is +2 e.
