B. Oil, water can be renewed but oil cannot
Eₖ = √1/2 mv²
Eₖ/v² = 1/2 m
2Eₖ/v² = m
mgh = 1/2 mv²
gh = 1/2 v²
2gh = v²
v = √2gh
= √2 × 10 N/kg × 2 m
= 6.324 ms⁻¹
m = 9.8/(6424)²
= 9.8/39.993
= 0.245 g
I am not sure if it's correct.
i transposed for m in the first equation then to find the velocity I combined the potential and kinetic energy equation. there was no mass because velocity doesn't depend on the mass
Then I used earth's gravitational field strength (g) 10 N/kg and the 2 m was the height provided in the question
you can try working and see if you get the same
