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cjb19
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Homework Statement
1.A block is sent up a frictionless ramp along which an x-axis extends upward. The figure below gives the kinetic energy of the block as a function of position x; the scale of the figure's vertical axis is set by Ks = 38.0 J. If the block's initial speed is 4.70 m/s, what is the normal force on the block?
2. A startled armadillo leaps upward rising 0.553 m in the first 0.197 s.
(a) What is its initial speed as it leaves the ground?
Correct: Your answer is correct. m/s
(b) What is its speed at the height of 0.553 m?
Correct: Your answer is correct. m/s
(c) How much higher does it go?
Homework Equations
F=ma
v^2=v0^2+2ad
The Attempt at a Solution
For the first question
KE=.5mv^2
152 J = .5m(4.70 m/s)^2
m=13.8 kg
Height of the ramp
.5mv^2=mgh
152 J=13.8kg*9.8m/s^2*h
h=1.13 m
Solve for the angle of the ramp
sin-1(1.13m/2m) = 34 deg
N-mgcos34=0
N=13.8*9.8cos34=111 N. But this is wrong.
2nd question...
solved pt a and b, got 3.77 m/s for v0, 1.84 m/s vf
v0 is 0 m/s at the top of the height, so
0=3.77m/s ^2 +2*9.8m/s^2d
solve for d, get .725
difference is .17 m. But this is wrong.
Thank you so much! Final monday and I have a C-:/