CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

A bullet of mass 50 g is fired from below into the bob of mass 450 g of a long simple pendulum, as shown in the figure. The bullet remains inside the bob and bob rises through a height of 1.8 m. Find the speed of the bullet.
[Take g=10 ms2]


A
60 ms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
180 ms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
36.6 ms1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
60 ms1
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

The correct option is D 60 ms1
Given, mbob=0.45 kg ; mbullet=0.05 kg
h=1.8 m


In collision, there is no external force involved. Thus, linear momentum of the system will be conserved.

Let initial velocity of the bullet and final velocity of (bob+bullet ) be v and V respectively.

Pi=Pf

(0.05×v)+(0.45×0)=(0.05+0.450)×V

0.05v=0.5V

V=v10

After collision, the system of (bob+pullet) rises to a height of 1.8 m.

Using kinematic equations,

v2=u2+2as

Here,
v=0; u=V; a=g; h=1.8 m

(0)2=(V)2+[2(10)×(1.8)]

V2=2×10×1.8

(v10)2=36

v=60 ms1

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, (D) is the correct answer.

flag
Suggest Corrections
thumbs-up
0
BNAT
mid-banner-image