Two blocks of masses 5 kg and 2 kg are connected by a spring of negilible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 7 m / s to the heavier block in the direction of the lighter block. The velocity of the centre of mass is

Question

Two blocks of masses 5 kg and 2 kg are connected by a spring of negilible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 7 m / s to the heavier block in the direction of the lighter block. The velocity of the centre of mass is (A) 30 m / s (B) 20 m / s (C) 10 m / s (D) 5 m / s

Tardigrade Admin · Accepted Answer

vcm =(m1 v1+m2 v2/m1+m2) =(5(7)+2(0)/7)=5 m / s

Q. Two blocks of masses $5 k g$ and $2 k g$ are connected by a spring of negilible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of $7 m / s$ to the heavier block in the direction of the lighter block. The velocity of the centre of mass is

30 m / s

20 m / s

10 m / s

5 m / s

$v_{c m} = \frac{m _{1} v _{1} + m _{2} v _{2}}{m _{1} + m _{2}}$
$= \frac{5 ( 7 ) + 2 ( 0 )}{7} = 5 m / s$

Q. Two blocks of masses 5kg and 2kg are connected by a spring of negilible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 7m/s to the heavier block in the direction of the lighter block. The velocity of the centre of mass is