1) The equivalent resistance of two resistors in parallel is given by:

so in our problem we have

and the equivalent resistance is

2) If we have a battery of 12 V connected to the circuit, the current in the circuit will be given by Ohm's law, therefore:
Answer:
10 kg
Explanation:
Assuming a frictionless surface, then force F=ma where F is the applied force, m is the mass and a is acceleration. Making m the subject of the formula then 
Substituting 100 N for the applied force F and 10 m/s^2 for acceleration a then the value of m will be 
Therefore, in terms of kilograms, the bookshelf weighs 10 Kg
Answer:
72 volts.
Explanation:
To solve this, we have to use the Ohm's law.
The ohm's law tells us that the voltage drop of a resistor is directly proportional to the current applied to the conductor.

in this case the current is 1.8 amps and the resistor is 40 ohm

so
.
The ultimate source of energy that powers the sun is the Mass energy of hydrogen fusing into helium, there is no other process than the annihilation of mass to give energy that has been advocated by Albert Einstein and it is capable of keeping the sun alive.
The answer is to the question is c