A student stands at the edge of a cliff and throws a stone horizontally over the
ID: 2109283 • Letter: A
Question
A student stands at the edge of a cliff and throws a stone
horizontally over the edge with a speed of 22.0 m/s. The cliff is
h = 63.0 m above a flat, horizontal beach as shown in the
figure.
"http://www.webassign.net/sercp9/3-p-023-alt.gif" alt=
"3-p-023-alt.gif" />
(a) What are the coordinates of the initial position of the
stone?
x0
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
m
y0
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
m
(b) What are the components of the initial velocity?
v0x
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
m/s
v0y
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
m/s
(c) Write the equations for the x- and y-components
of the velocity of the stone with time. (Use the following as
necessary: t. Let the variable t be measured in
seconds. Do not state units in your answer.)
vx
=
"waMark single mCorrect">
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
vy
=
"waMark single mIncorrect">
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Incorrect: Your answer is incorrect." title=
"Your answer is incorrect." />
(d) Write the equations for the position of the stone with time,
using the coordinates in the figure. (Use the following as
necessary: t. Let the variable t be measured in
seconds. Do not state units in your answer.)
x
=
"waMark single mIncorrect">
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Incorrect: Your answer is incorrect." title=
"Your answer is incorrect." />
y
=
"waMark single mIncorrect">
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Incorrect: Your answer is incorrect." title=
"Your answer is incorrect." />
(e) How long after being released does the stone strike the beach
below the cliff?
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
s
(f) With what speed and angle of impact does the stone land?
vf
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
m/s
ÃŽ ¸
=
"http://www.webassign.net/static/wacache73278a4a86960eeb576a8fd4c9ec6997/img/questions/markSprite.png"
alt="Correct: Your answer is correct." title=
"Your answer is correct." />
 °
below the horizontal
Explanation / Answer
vx (speed in horizontal direction) = 22m/s (constant) uy (initial vertical speed) = 0 s (distance) = 63m a (grav rate) = 9.8m/s/s Use s = ut + (at^2)/2 to find t (time taken to fall vertically) 63 = 0 + (9.8t^2)/2 9.8t^2 = 126 t = 3.58s We know horizontal speed is constant. So find out how fast it will accelerate to vertically in 3.13s using v^2 = u^2 + 2as v^2 = 0 + 2 x 9.8 x 63 v (vertical) = 35.139m/s Using vertical and horizontal speeds, calculate the vector (a^2 = b^2 + c^2) v^2 = 35.139^2 + 22^2 = 1424.8 v = 41.45/s is the speed it hits the beach. Use v(total) = v(horizontal) cos x to find angle x 41.45 = 22 cos x cos x = 1.88 x = cos^-1(1.88)
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.