Yes, I misunderstood the question; he has to look at the ice from the air to the water. They did not provide a diagram; I uploaded the one I had understood earlier. Sorry for the confusion.
It is a multiple-choice question. there is an answer with 9 cm.
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook.
Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height...
Proof of kinetic energy
work done equals a change in kinetic energy in a mechanical system.
δW = F.ds
W = ∫F.ds
W = m∫a.ds
W = m∫(dv/dt).ds
W = m∫v.dv
here if v and dv are in the same direction the change in kinetic energy will be the usual equation. what happens if both are in different...