Direction for: In each of the following questions a statement of Assertion is given followed by a corresponding statement of Reason just below it. Of the statements mark the correct answer as
Assertion: A body is projected vertically upwards with velocity 10 ms-1. It reaches the maximum vertical height h in time t. In the height covered is\[\frac{3h}{4}\] Reason :\[t=\sqrt{\frac{2h}{g}}\,and\,\,{{v}^{2}}={{u}^{2}}+2gh\]A) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C) If Assertion is true but Reason is false.
D) If both Assertion and Reason are false.
Correct Answer: A
Solution :
\[t=\sqrt{\frac{2h}{g}}\] \[s=10\times \frac{t}{2}-\frac{1}{2}g\frac{{{t}^{2}}}{4}\] \[=5\sqrt{\frac{2h}{g}}-\frac{g}{g}\frac{2h}{g}\] \[{{v}^{2}}-{{u}^{2}}=2gh\] or \[100=2gh\] or \[10=\sqrt{2gh}\] \[s=\frac{\sqrt{2gh\times 2h}}{4\times g}-\frac{h}{4}\] \[=h-\frac{h}{4}=\frac{3h}{4}\]
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