A) 2 m/sec
B) 3 m/sec
C) 2.5 m/sec
D) 1.5 m/sec
Correct Answer: A
Solution :
According to fig. \[{{x}^{2}}+{{y}^{2}}=25\] .....(i) Differentiate (i) w.r.t. t, we get \[2x\frac{dx}{dt}+2y\frac{dy}{dt}=0\] ?..(ii) Here \[x=4\] and \[\frac{dx}{dt}=1.5\] From (i), \[{{4}^{2}}+{{y}^{2}}=25\Rightarrow y=3\] \[\therefore \] From (ii), \[2(4)(1.5)+2(3)\frac{dy}{dt}=0\] So, \[\frac{dy}{dt}=-2m/\sec \] Hence, length of the highest point decreases at the rate of 2m/sec.You need to login to perform this action.
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