Bats use ultrasound in echolocation. this sound is characterized by
low frequency
low amplitude
high frequency
high amplitude

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?

Aball horizontally thrown from a cliff at 8m/s

A1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km. what is the magnitude of the friction force required to keep the car from sliding?