Question

M1=20kg
M2= 750kg
U1= 20m/s
U2= 15m/s
V1= 10m/s
V2= ?

Answer 1

Solution:

According to the law of conservation of momentum:

$M_1\upsilon_1+M_2\upsilon_2=M_1u_1+M_2u_2$

$M_2\upsilon_2=M_1u_1+M_2u_2-M_1\upsilon_1$

Then:

$\upsilon_2=\frac{M_1u_1+M_2u_2-M_1\upsilon_1}{M_2}=\frac{M_1}{M_2}(u_1-\upsilon_1)+u_2$

$\upsilon_2=\frac{20}{750}(20-10)+15=15.27$ m/s.

Answer:

$\upsilon_2$ = 15.27 m/s.