Suppose you drop a rock into a dark well and, using precision equipment, you measure the time for the sound of a splash to return. (a) Neglecting the time required for sound to travel up the well, calculate the distance to the water if the sound returns in 2.0000 s. (b) Now calculate the distance taking into account the time for sound to travel up the well. The speed of sound is 332.00 m/s in this well.

13. A hiker walks 10.0 km (NEJ. 5.0 km [W]. and then 2.0 km [S] in 2.5 h. (a) What is the hiker's displacement? (b) In what direction must the hiker set out, in order to return by the most direct route to the starting point? (c) If the hiker walks at a constant speed for the entire trip and retums by the most direct route, how long will the total walk take?

III. 16. The floor area of a Boeing 707-230 is 106 m2. Express this area in ft2. 17. Convert a speed of 45 mph to fps. 18. The Silver Sabre has a maximum rate of climb of 4800 ft/min. Determine the rate of climb in ft/s ... sneed 21

Automobile traffic passes a point P on a road of width w feet at anaverage rate of R vehicles per second. Although the arrival of automobilesis irregular, traffic engineers have found that the average waiting time Tuntil there is a gap in traffic of at least t seconds is approximately T = t eRtseconds. A pedestrian walking at a speed of 3.5 ft/s (5.1 miles per hour) requires t = w /3.5 s to cross the road . Therefore, the average time the pedestrian will have to wait before crossing is f(w, R) = (w/3.5)ewR / 3. 5 s.(a) What is the pedestrian's average waiting time if w = 25 ft and R = 0.2 vehicle per second?(b) Use the Linear Approximation to estimate the increase in waiting timeif w is increased to 27 ft.( c) Estimate the waiting time if the width is increased to 27 ft and R decreases to 0.18.( d) What is the rate of increase in waiting time per 1-ft increase in widthwhen w = 30 ft and R = 0.3 vehicle per second?

Two airplanes leave an airport at the same time. The velocity of the first airplane is 710 m/h at a heading of 37.1º The velocity of the second is 630 m/h at a heading of 177◦ How far apart are they after 1.8 h? Answer in units of m.

Traffic shock wave. An abrupt slowdown in concentratedtraffic can travel as a pulse, termed a shock wave, along theline of cars, either downstream (in the traffic direction) or upstream,or it can be stationary shows a uniformlyspaced line of cars moving at speed v = 25.0 m/s toward a uniformlyspaced line of slow cars moving at speed vs = 5.00 m/s.Assume that each faster car adds length L = 12.0 m (car lengthplus buffer zone) to the line of slow cars when it joins the line, and assumeit slows abruptly at the last instant. (a) For what separation distanced between the faster cars does the shock wave remainstationary? If the separation is twice that amount, what are the (b)speed and (c) direction (upstream or downstream) of the shock wave?

(4) An object has a velocity of (5.4 m/s) i – (4.8 m/s) j. Over a period of 1.3 s, its velocity changes to (1.7 m/s) i + (5.9 m/s) j. What is its A) average acceleration? -(3.7 m/s). + (11 m/s) j B) -(2.8 m/s) + (8.2 m/s)? C) (3.7 m/s)' + (11 m/s) D) (2.8 m/s)? + (8.2 m/s) E) (2.8 m/s)' + (1.1 m/s)

72) (a) Calculate the height of a cliff if it takes 2.35 s for a rock to hit the ground when it is thrown straight up from the cliff with an initial velocity of 8.00 m/s. (b) How long a time would it take to reach the ground if it is thrown straight down with the same speed? ution S

(II) A horse trots away from its trainer in a straight line, moving 38 m away in 9.0 s. It then turns abruptly and gallops halfway back in 1.8 s. Calculate (a) its average speed and (b) its average velocity for the entire trip, using“away from the trainer” as the positive direction