CBSE-IX-Science
03: 1-Forces and Laws of Motion
Qstn# II-4 Prvs-Qstn
- #4Two objects of masses 100 g and 200 g are moving along the same line and direction with velocities of
and
, respectively. They collide and after the collision, the first object moves at a velocity of 
. Determine the velocity of the second object.Ans : Given,
= 100g = 0.1 kg
= 200g = 0.2 kg
velocity of the first object =
= 2 m/s
velocity of the second object =
= 1 m/s
Momentum before the collision =
= 0.4 kg m/s
since velocity of first object after collision = 1.67m/s
If we suppose that velocity of second object = v
As per law of conservation of momentum,
= (initial momentum = final momentum)
0.4 = 0.167 + 0.2v
0.2v = 0.4 -0.167
v = ``\frac{0.2333}{0.2} = \frac{2.33}{2} = 1.16 m/s``