A particle is projected vertically upward. The value of g is\[10\text{ }m/se{{c}^{2}}\]. If 10 and 16 seconds be the times at which it is at the same height while ascending and descending respectively. Then velocity of projection is
A) 260 m/sec
B) 160 m/sec
C) 130 m/sec
D) 110 m/sec
Correct Answer:
C
Solution :
: Time for reaching highest point \[=\frac{16-10}{2}+10=13\,\sec \] \[\therefore \] \[v=u-gt\] \[0=u-gt\] Or \[u=gt\] \[=10\times 13\] \[=130\text{ }m/s.\]