A convertible with the top down is traveling north on a road at a speed of 27.0 m/s. An ambulance, traveling south at a speed of 47.0 m/s, approaches with its siren producing sound at a frequency of 2450 Hz. (Enter your answers in Hz. Assume that the speed of sound in air is 343 m/s.)

(a)

What frequency does the driver of the convertible observe as the ambulance approaches? (Enter your answer to the nearest integer.)

Hz

(b)

What frequency does the driver of the convertible detect after the ambulance passes her?

Hz

(c)

Repeat parts (a) and (b) for the case when the ambulance is traveling northbound.

i.)while ambulance overtakes (Hz)

ii.)after ambulance passes

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

When you jump from an elevated position you usually bend your knees upon reaching the ground. by doing this, you make the time of the impact about 10 times as great as for a stiff-legged landing. in this way the average force your body experiences is a) less than 1/10 as great. b) more than 1/10 as great. c) about 1/10 as great.d) about 10 times as great.

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.