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A person going for a morning jog on the deck of a cruise ship isrunning toward the bow (front) of the ship at 2.0 m/s while theship is moving ahead at 9.0 m/s.

What is the speed of the jogger relative to the water?
Later, the jogger is moving toward the stern (rear) of the ship.What is the jogger's speed relative to the water now?

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Lelia Lubowitz
Lelia LubowitzLv2
3 Jan 2019

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Related textbook solutions

Physics: Principles with Applications
7th Edition, 2013
Giancoli
ISBN: 9780321625922

Related questions

Learning Goal: To understand length contraction and timedilation.

An inertial frame of reference is one in which Newton's laws hold.Any frame of reference that moves at a constant speed relative toan inertial frame of reference is also an inertial frame. Theproper length l_0 of an object is defined to be the length of theobject as measured in the object's rest frame. If the length of theobject is measured in any other inertial frame, moving with speed urelative to the object's rest frame (in a direction parallel tol_0), the resulting length l is given by the length contractionequation

l = l_0\sqrt{1-\frac{u^2}{c^2}} ,

where c is the speed of light. Similarly, if two events occur atthe same spatial point in a particular reference frame, and anobserver at rest in this frame measures the time interval betweenthese two events, the time interval so measured is defined to bethe proper time Delta t_0. When the time interval is measured inany other inertial frame, again moving with speed u relative to thefirst frame, the resulting time interval Delta t is given by thetime dilation equation

\Delta t = \frac{\Delta t_0}{\sqrt{1-\frac{u^2}{c^2}}} .

a. Suppose that you measure the length of a spaceship, at restrelative to you, to be 400 \rm m. How long will you measure it tobe if it flies past you at a speed of u = 0.75c?
Express the length l in meters to three significant figures.

b. The spaceship from Part A has a large clock attached to itsside. This clock ran at the same rate as your watch when you werein the same reference frame. How much time Delta t will pass onyour watch as 80 \rm s passes on the clock attached to theship?
Express your answer in seconds to three significant figures.

c. Two spaceships, named A and B, are flying toward each other withrelative speed 0.800c. If the captain of ship A fires a missile,counts 10.0 \rm s on his watch, and then fires a second missile,how much time Delta t will the captain of ship B measure to havepassed between the firing of the two missiles?
Express your answer in seconds to three significant figures.

d. The captain of ship B knows that ship A uses 2-m-long missiles.She measures the length of the first missile, once it has finishedaccelerating, and finds it to be only 0.872 \rm m long. What is thespeed u of the missile, relative to ship B?
Express your answer in meters per second to three significantfigures. Use c = 3 \times 10^8 \; \rm m/s.

Please answer fully... thank you

In the figure below, an albatross glides at a constant 14 m/shorizontally above level ground, moving in a vertical plane thatcontains the Sun. It glides toward a wall of height h = 3.5 m,which it will just barely clear. At that time of day, the angle ofthe Sun relative to the ground is ? = 21°.

Figure: http://www.webassign.net/hrw8/33-77.gif

(a) At what speed does the shadow of the albatross move across thelevel ground?

(b) At what speed does the shadow of the albatross move up thewall?

Suppose that later a hawk happens to glide along the same path,also at 14 m/s. You see that when its shadow reaches the wall, thespeed of the shadow noticeably increases.

(c) Is the Sun now higher or lower in the sky than when thealbatross flew by earlier?

(d) If the speed of the hawk's shadow on the wall is 50 m/s, whatis the angle ? of the Sun just then?

vf = vi + at
rx = vit + ½ at2
vf2 = vi2 +2arx
rx = ½ (vi + vf)t

4. A sailboat is moving across the water at 3.0 m/s. A gust of windfills its sails and it accelerates at a constant 2.0 m/s2. At thesame instant, a motorboat at rest starts its engines andaccelerates at 4.0 m/s2. After 3.0 seconds have elapsed, find thevelocity of (a) the sailboat, and (b) the motorboat.



7. A rail gun uses electromagnetic energy to accelerate objectsquickly over a short distance. In an experiment, a 2.00 kgprojectile remains on the rails of the gun for only 2.10x10-2 s,but in that time it goes from rest to a velocity of 4.00×103 m/s.What is the average acceleration of the projectile?



12. A space shuttle sits on the launch pad for 2.0 minutes, andthen goes from rest to 4600 m/s in 8.0 minutes. Treat its motion asstraight-line motion. What is the average acceleration of theshuttle (a) during the first 2.0 minutes, (b) during the 8.0minutes the shuttle moves, and (c) during the entire 10 minuteperiod? (be careful with min and seconds)



19. The United States and South Korean soccer teams are playing inthe first round of the World Cup. An American kicks the ball,giving it an initial velocity of 3.6 m/s. The ball rolls a distanceof 5.0 m and is then intercepted by a South Korean player. If theball accelerates at -0.50 m/s2 while rolling along the grass, findits velocity at the time of interception.




23. The city is trying to figure out how long the traffic lightshould stay yellow at an intersection. The speed limit on the roadis 45.0 km/h and the intersection is 23.0 m wide. A car istraveling at the speed limit in the positive direction and canbrake with an acceleration of -5.20 m/s2. (a) If the car is to stopon the white line, before entering the intersection, what is theminimum distance from the line at which the driver must apply thebrakes?



**(b) How long should the traffic light stay yellow so that if thecar is just closer than that minimum distance when the light turnsyellow, it can safely cross the intersection without having tospeed up?

I no this is alot of questions but im having trouble answeringthese! So please help me..

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