(i) Clouds appear white. (ii) Sky appears blue.
(i) Name the system which enables us to locate
underwater objects by transmitting ultrasonic
waves and detecting the reflecting impulse. [3]
(ii) What are acoustically measurable quantities
related to pitch and loudness ?
(i) When a tuning fork [vibrating] is held close
to ear, one hears a faint hum. The same (vibrating
tuning fork] is held such that its stem is in contact
zuith the table surface then one hears a loud sound

This problem has been solved! see the answera non-uniform fire escape ladder is 6.0m long whenextended to the icy alley below. it is held at the top by africtionless pivot, and there is neglibible frictional force fromthe icy surface at the bottom. the ladder weighs 250n, and it'scenter of gravity is 2.0m along the ladder from the bottom. amother and child of total weight 750n are on the ladder 1.5m fromthe pivot. the ladder makes an angle θ with the horizontal. find the magnitude and direction ofa) the force exerted by the icy alley on the ladderb) the force exerted by the ladder on the pivotc) do your answers in part a and b depend on the angle?

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)