JEE Main & Advanced
Physics
Motion in a Straight Line / सरल रेखा में गति
Question Bank
Motion Under Gravity
question_answer
A body projected vertically upwards with a velocity \[u\] returns to the starting point in 4 seconds. If \[g=10\]m/sec2, the value of \[u\] is [KCET 1999]
A) 5 m/sec
B) 10 m/sec
C) 15 m/sec
D) 20 m/sec
Correct Answer:
D
Solution :
Time of flight \[T=\frac{2u}{g}=4\ \sec \Rightarrow u=20\ m/s\]