Question 120: Laws of Motion

Question

An insect is at the bottom of a hemispherical ditch of radius 1 m. It crawls up the ditch but starts
slipping after it is at height h from the bottom. If the coefficient of friction between the ground and
the insect is 0.75, then h is : 
(g = 10 ms–2)

Accepted Answer

For balancing mgsin $$	heta $$ = f
mgsin $$	heta $$ = $$\mu $$mgcos $$	heta $$
$$ \Rightarrow $$ tan $$	heta $$ = $$\mu $$ = $${3 \over 4}$$
h = R Ã¢ÂÂ R cos$$	heta $$
= R - R$$\left( {{4 \over 5}} ight)$$ = $${R \over 5}$$
$$ 	herefore $$ h = $${R \over 5}$$ = $${1 \over 5}$$ = 0.2 m

Answer

0.45 m

Answer

0.60 m

Answer

0.20 m

Answer

0.80 m

Laws of Motion

An insect is at the bottom of a hemispherical ditch of radius 1 m. It crawls up the ditch but starts slipping after it is at height h from the bottom. If the coefficient of friction between the ground and the insect is 0.75, then h is : (g = 10 ms–2)

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