# Relative Motion Extra Practice Problems

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14 Νοε 2013 (πριν από 4 χρόνια και 6 μήνες)

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Relative Motion Extra Practice Problems

1.

A conductor is collecting tickets on a train traveling 35 m/s to the right. If he walks at a speed of
1 m/s, what is his velocity relative to an outside observer as he walks to the left collecting
tickets? If he
returns back up the train at the same speed, determine his relative velocity again.

2.

Logan takes his fiancé MarySue on a romantic date on a rowboat. Logan can row at 3.0 m/s in
still water, yet is experiencing a current of 7.0 m/s as he crosses a river
. What is his relative
velocity to the shore?

a.

If the river is 25 meters wide, how far downstream do Logan and MarySue land from
their starting point?

3.

An airplane is flying North at a speed of 325 mph, yet experiences a wind from the West at a
speed

of 85 mph. What is the airplane’s velocity relative to the ground, including magnitude and
direction?

4.

An airport has a moving sidewalk that operates at a speed of 3.0 m/s. If a bug aims directly
across the 1.0
-
meter wide track at a spee
d of 0.143 m/s,
will it reach the other side before the
end of the 25
-
meter long sidewalk?

a.

If a person is standing outside the moving sidewalk, at what speed will they observe the
bug traveling?

5.

A train is traveling to the East at a speed of 20 m
/s. On the train, Tommy and Brian decide to
have a catch. They throw the ball back and forth, each throwing the ball at 22.07 m/s at an angle
of 10 degrees above the horizontal. Determine the following relative velocities:

a.

Ball relative to another passeng
er on the train:

b.

Ball relative to an observer outside the train:

c.

Ball relative to an observer outside the train when Brian throws it back:

d.

Outside observer relative to Tommy:

6.

A kayaker wants to travel directly across a river that h
as a current of 8.0 m/s downstream. If he
can paddle at 12 m/s in still water, at what angle must he aim upstream to land directly across?

7.

An airplane wants to travel due South, yet is experiencing a strong Easterly wind (from the
West) at a speed of 95

mph. In what direction should the pilot aim the plane at a speed of 400
mph so that the plane actually travels due South?

8.

A Mississippi River paddleboat can travel at a speed of 14 m/s in still water. While moving down
the mighty Mississippi, which has

a current of 9.0 m/s, the paddleboat can angle its course a
maximum of 5 degrees from downstream. If it maintains this maximum angle, what is the boat’s
velocity relative

to the shore?

9.

If the paddleboat from Problem 8 wants to land directly across the
Mississippi, at what angle
upstream must it aim?

10.

Jack and Teddy are playing with the Harlem Globetrotters and are practicing a trick pass. While
jogging at each other with

a speed of 3.0 m/s
, Jack tosses the ball straight up at a speed of 2.3
m/s. In or
der for Teddy to catch it at the same release height, how far apart must they be when
Jack releases the ball?