JEE Main & Advanced
Physics
Motion in a Straight Line / सरल रेखा में गति
Question Bank
Self Evaluation Test - Motion in a Strainght Line
question_answer
From a balloon moving upwards with a velocity of \[12\text{ }m{{s}^{-1}}\], a packet is released when it is at a height of 65 m from the ground. 7 lie time taken by it to reach the ground is \[(g=10\text{ }m{{s}^{-2}})\]
A)5s
B)8s
C)4s
D)7s
Correct Answer:
A
Solution :
\[s=ut+\frac{1}{2}a{{t}^{2}}\] \[-65=12t-5{{t}^{2}}\]on solving we get, t=5s