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Mechanics, PHY 101 Figure 4-39 Problem 42.
4
5
m 38.
nd level at-
t edge of the
round 1.50 s
gle u ! 60.0°
h
em 39.
t the worldWhat horiangle #0 is
he angle of
oes not maxnding are at
Date: 26 September 2022
Date: 412October
October2021
2020
••43 ILW A ball is shot from the ground into
the air. 3
At a height
Tutorial
of 9.1 m, its velocity is :
v ! (7.6î " 6.1ĵ) m/s, with î horizontal and ĵ
upward. (a) To what maximum height does the ball rise? (b) What
o
1. In
Fig. 1 , adistance
ball is launched
with
a velocity
magnitude
total
horizontal
does the
ball
travel? of
What
are the10.0 m/s, at an angle of 50.0 to
(c) magnitude
and (d) The
anglelaunch
(belowpoint
the horizontal)
of theofball’s
ve- of horizontal length d = 6.00
the horizontal.
is at the base
a ramp
1
locity just before it hits the ground?
m and height d = 3.60 m. A plateau is located at the top of the ramp.
2
••44 A baseball leaves
a pitcher’s hand horizontally at a speed of
161 km/h.The distance to the batter is 18.3 m. (a) How long does the
(a)to travel
Does the
ball half
landofon
the
ramp or(b)
the
plateau?
ball take
the first
that
distance?
The
second half?
(c) How far does the ball fall freely during the first half? (d) During
(b) half?
When(e)
it Why
lands,aren’t
whatthe
arequantities
the magnitude
and(d)
angle
of its displacement from the launch
the second
in (c) and
equal?
point?
••45 In Fig.
4-40, a ball is launched with a velocity of magnitude
10.0 m/s, at an angle of 50.0° to the horizontal. The launch point is at
the base of a ramp of horizontal length d1 ! 6.00 m and
height d2 ! 3.60 m. A plateau
v0
d2
is located at the top of the
Ball
ramp. (a) Does the ball land on
d1
the ramp or the plateau? When
it lands, what are the (b) magFigure 4-40 Problem 45.
nitude and (c) angle of its displacement from the launch point? FIG. 1: Figure for Question 1.
••46
In basketball, hang is an illusion in which a player
seems to weaken the gravitational acceleration while in midair. The
2. When looping the loop, the Blue Angels stunt pilots of the U.S. Navy fly their jet aircraft
illusion depends much on a skilled player’s ability to rapidly shift
along a vertical circle of diameter 1000 m. At the top of the circle, the speed is 350 km/h;
at the bottom of the circle, the speed is 620 km/h. What is the centripetal acceleration
at the top? At the bottom? In the reference frame of one of these aircraft, what is the
acceleration that the pilot feels at the top and at the bottom; i.e., what is the acceleration
relative to the aircraft of a small body, such as a coin, released by the pilot?
3. A swimmer is capable of swimming 0.60 m/s in still water.
(a) If she aims her body directly across a 45 m wide river whose current is 0.50 m/s, how
far downstream (from a point opposite her starting point) will she land?
(b) How long will it take her to reach the other side?
(c) At what upstream angle must the swimmer aim if she is to arrive at a point directly
across the stream? How long will it take her?
4. A lump of concrete falls off a crumbling overpass and strikes an automobile traveling on a
highway below. The lump of concrete falls 5.0 m before impact, and the automobile has
a speed of 90 km/h.
Date: 412October
October2021
2020
1
Mechanics, PHY 101
Date: 26 September 2022
Date: 412October
October2021
2020
(a) What is the speed of impact of the lump in the reference frame of the automobile?
(b) What is the angle of impact?
Date: 412October
October2021
2020
2