Which to the following is NOT a fundamental unit?

A projectile fired with initial velocity, u will attain its maximum height H when the angle of projection θ is

For total internal reflection to occur,

I. light must be travelling from an optically more dense to an optically less dense medium.
II. the angle of incidence in the denser medium must be greater than its critical angle.
III. the angle of refraction in the less dense medium must be equal to 90 °. Which of the statements above is/are correct?

Which property of a fluid determines its suitability as a lubricant?

A note, A from a guitar produces a wave of amplitude 4 mm and frequency 1000 Hz. Another note, B from a whistle produces a similar waveform of amplitude 2 mm and frequency 2200 Hz. If the two notes are compared,