Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m/s before the collision during which they stick together. What will be the velocity of the combined object after collision?
Given
mass of the first object (m1) = 1.5 kg
velocity of the first object (u1) before collision = 2.5 m/s
mass of the second object (m2) = 1.5kg
velocity of the second object (u2) before collision = -2.5 m/s
The negative sign indicates the second object moves in direction opposite to the first one.
mass of the combined objects after collision (m3) = m1+ m2= 3.0 kg
velocity of the combined objects after collision (v3) =?
Being an isolated system, total momentum is conserved i.e.
(m1u1) + (m2u2) = (m3v3)
⇒ (1.5 × 2.5) + (1.5 × -2.5) = 3.0 × v3
⇒ 0 = 3.0 × v3
⇒ v3 = 0 m/s
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| Time(s) | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|
| Distance (m) | 0 | 1 | 8 | 27 | 64 | 125 | 216 | 343 |
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The following is the distance-time table of an object in motion:
| Time in seconds | Distance in meters |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 27 |
| 4 | 64 |
| 5 | 125 |
| 6 | 216 |
| 7 | 343 |
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