Question

# A wooden block of mass 10 g is dropped from the top of a cliff 100 m high. Simultaneously, a bullet of mass 10 g is fired from the foot of the cliffupward with a velocity of 100 msâˆ’1. At what time will the bullet and the block meet ?

A
4 s
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
B
3 s
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
C
2 s
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
D
1 s
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

## The correct option is D 1 sHeight of the tower =s1+s2=100 m. Where s1 and s2 are the displacements covered by wooden block and bullet respectively before the collision. For the block : s1=12gt2=12×9.8×t2=4.9t2 For the bullet : s2=ut−12gt2 =100t−12×9.8×t2=100t−4.9t2 Since, s1+s2=100 m 4.9t2+100t−4.9t2=100 ⇒ 100t = 100 ⇒ t = 1s.

Suggest Corrections
33
Join BYJU'S Learning Program
Select...
Related Videos
Equations of Motion
PHYSICS
Watch in App
Explore more
Join BYJU'S Learning Program
Select...