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Problem
Problem
An open knife of mass
m
m
m
is dropped from a height
h
h
h
on a wooden floor. If the blade penetrates up to the depth
d
d
d
into the wood, the average resistance offered by the wood to the knife edge is a.
m
g
(
1
+
h
d
)
mg \left(1 + \frac{h}{d}\right)
m
g
(
1
+
d
h
)
b.
m
g
(
1
+
h
d
)
2
mg \left(1 + \frac{h}{d}\right)^2
m
g
(
1
+
d
h
)
2
c.
m
g
(
1
−
h
d
)
mg \left(1 - \frac{h}{d}\right)
m
g
(
1
−
d
h
)
d.
m
g
(
1
+
d
h
)
mg \left(1 + \frac{d}{h}\right)
m
g
(
1
+
h
d
)
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