What is the work done by gravity as a 10 kg object falls from rest at 12m to 5m?

686 joules

Explanation:

Work done = ?

Mass of fallen object = 10 kg

Height = (12m - 5m) = 7metres

(The height is 7metres because the object fell from an height of 12m to 5m)

Acceleration due to gravity g = 9.8m/s2

Workdone = Mass x Acceleration due to gravity x height

= 10kg x 9.8m/s2 x 7 metres

= 686 joules

Thus, the work done by gravity is 686 joules

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.