The correct answer is: The voltage drop across

is
45V.Explanation:First you need to find the total current of the circuit, which is:
According to Ohm's law:
V = I * R
I = V/R --- (1)
Where
R = Total Equivalent resistance of the circuit
V = Total Voltage = 90V
I -= Total Current
First let us find the equivalent resistance:

Now plug in the values in (1):
(1) => I = 90/30 = 3A
Now that we have current of the circuit, we can now find the voltage
drop across

= 15 ohms using:

Where

is the voltage drop across resistor 5;
Redox reactions( oxidation-reduction reaction)
I don't know for sure but i think that it is because the force him pushing her pushed him back as well
Hope i helped
F=ma
For the first (10kg) cart,
12=10a
a=6/5 m/s^2 to the left
For the second (5kg) cart,
8=5a
a=8/5 m/s^2 to the left
Therefore, the lighter (5kg) cart experiences a greater acceleration.