A body of mass m1 collides elastically with another body of mass m2 at rest. If the velocity of m1 after collision becomes 2/3 times its initial velocity, the ratio of their masses, is

Question

A body of mass m1 collides elastically with another body of mass m2 at rest. If the velocity of m1 after collision becomes 2/3 times its initial velocity, the ratio of their masses, is (A)  1:5  (B)  5:1  (C)  5:2  (D)  2:5

Tardigrade Admin · Accepted Answer

In elastic collision v1((m1-m2/m1+m2)) u1+((2 m2/m1+m2)) u2 If the second ball is at rest, ie, u2=0, then v1((m1-m2/m1+m2)) u1 Given v1=(2/3) u1 (2/3) u1=((m1-m2/m1+m2)) u1 ⇒ 2 m1+2 m2=3 m1-3 m2 ⇒ m1=5 m2 ⇒ (m1/m2)=(5/1)

Q. A body of mass $m_{1}$ collides elastically with another body of mass $m_{2}$ at rest. If the velocity of $m_{1}$ after collision becomes $2/3$ times its initial velocity, the ratio of their masses, is

$1 : 5$

$5 : 1$

$5 : 2$

$2 : 5$

Q. A body of mass m1​ collides elastically with another body of mass m2​ at rest. If the velocity of m1​ after collision becomes 2/3 times its initial velocity, the ratio of their masses, is

1:5

5:1

5:2

2:5

Q. A body of mass $m_{1}$ collides elastically with another body of mass $m_{2}$ at rest. If the velocity of $m_{1}$ after collision becomes $2/3$ times its initial velocity, the ratio of their masses, is

$1 : 5$

$5 : 1$

$5 : 2$

$2 : 5$