A playground is on the flat roof of a city school, hb = 5.40 m
above...
A playground is on the flat roof of a city school, hb = 5.40 m
above the street below (see figure). The vertical wall of the
building is h = 6.60 m high, to form a 1.2-m-high railing around
the playground. A ball has fallen to the street below, and a
passerby returns it by launching it at an angle of θ = 53.0° above
the horizontal at a point d = 24.0 m from the base of the building
wall. The ball takes 2.20 s to reach a point vertically above the
wall.
A man on the ground kicking a ball to children on a flat
rooftop is shown. The distance between the man and the building is
labeled d. The height of the left wall of the building is labeled
h. The motion of the ball is depicted as a parabola originating
from the man on the ground and ending at the rooftop. The vector of
the initial motion of the ball makes an angle θ with the
horizontal.
(a) Find the speed at which the ball was launched.
m/s
(b) Find the vertical distance by which the ball clears the
wall.
m
(c) Find the horizontal distance from the wall to the point on
the roof where the ball lands.
A playground is on the flat roof of a city school, 4.9 m above
the street below (see figure). The vertical wall of the building is
h = 6.40 m high, to form a 1.5-m-high railing around the
playground. A ball has fallen to the street below, and a passerby
returns it by launching it at an angle of θ = 53.0° above
the horizontal at a point d = 24.0 m from the base of the
building wall. The...
A playground is on the flat roof of a city school, 6.00 m above
the street below. The vertical wall of the building is 7.00 m high,
forming a 1.00 m high railing around the playground. A ball has
fallen to the street below, and a passerby returns it by launching
it at an angle of 53.0° above the horizontal at a point 28.0 m from
the base of the building wall. The ball takes 2.10 s to reach a...
A playground is on the flat roof of a city school, 6.5 m above
the street below (see figure). The vertical wall of the building is
h = 7.80 m high, forming a 1.3-m-high railing around the
playground. A ball has fallen to the street below, and a passerby
returns it by launching it at an angle of θ = 53.0° above the
horizontal at a point d = 24.0 m from the base of the building
wall. The ball...
Children playing in a playground on the flat roof of a city
school lose their ball to the parking lot below. One of the
teachers kicks the ball back up to the children as shown in the
figure below. The playground is 5.50 m above the parking lot, and
the school building's vertical wall is
h = 6.90 m
high, forming a 1.40 m high railing around the playground. The
ball is launched at an angle of
θ = 53.0°...
A flat cushion of mass m is released from rest at the
corner of the roof of a building, at height h. A wind
blowing along the side of the building exerts a constant horizontal
force of magnitude F on the cushion as it drops as shown
in the figure below. The air exerts no vertical force.
(A) Show that the path of the cushion is a straight line.
(Submit a file with a maximum size of 1 MB.)
(B)...
A squirrel sitting on a peak of a roof which is 1.50 m above the
bottom of the roof and 4.50 m above the ground puts an acorn on the
roof. It starts from rest at the peak and slides down the sloped
roof (coefficient of friction = 0.150) which is angled at 25.0
degrees to the horizontal. After the acorn reaches the edge of the
roof it flies off and becomes a projectile. You may ignore air
resistance. Part...
A hurricane wind blows across a 7.50 m × 11.2 m flat roof at a
speed of 190 km/hr.a) Is the air pressure above the roof higher or lower than the
pressure inside the house? Explain.b) What is the pressure difference?c) How much force is exerted on the roof?d) If the roof cannot withstand this much force, will it “blow in”
or “blow out”?
The urban air above the city of Shanghai if the mixing height
above the city is 1210 m, the width of the box perpendicular to the
wind is 105 m, the average annual wind speed is 15,400 m/hr, and
the amount of sulfur dioxide discharged is 1375 × 106 lb/yr. Is
this a conservative or non-conservative system? State all
assumptions. Sketch a diagram to represent the system. Write the
complete mass balance for SO2. Estimate the SO2 concentration in
the...
A small bouncy ball is dropped from the flat roof of an
abandoned, and as-yet unrepurposed industrial building. The ball is
observed to take 1/8 of a second to fall across a broken window
with the total height of 1.2m. After the ball hits the ground, it
bounces back upward and again traverses the window’s height in 1/8s
of a second on its way toward the top of the roof. We thus assume
that the ball loses no energy upon...
While a roofer is working on a roof that slants at 45.0 ∘∘ above
the horizontal, he accidentally nudges his 90.0 NN toolboxes,
causing it to start sliding downward, starting from rest.
a)If it starts 4.70 mm from the lower edge of the roof, how fast
will the toolbox be moving just as it reaches the edge of the roof
if the kinetic friction force on it is 19.0 NN ?