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Physics Question Help! Urgent!
- Thread starter darkpichu
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Q7) the answer is D. The upward direction is taken as positive. Therefore, the direction of acceleration is always downward, which will then be negative throughout. The collision is elastic so it will make the same time for ball to move from the hand to ceiling and back from ceiling to hand. Thus, peak should be in between 1.2s.
Q8)
Q8)
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Change in momentum = initial momentum - final momentum (in this case), ie, mv1 - (-mv2) , -ve mv2 because the 2 velocities are in opposite directions.
Because the collision is inelastic, the final velocity will reduce.
In case of A, the change in momentum is below minimum change in momentum achievable, ie 2mv. so incorrect
In case of B, the change in momentum will be 2mv when final velocity is zero. However, ball rebonds with some velocity thus making B incorrect.
In case of C, the change in momentum will be 3mv when final velocity is v/2. This is reasonable thus correct.
In case of D, the change in momentum will be 4mv only when the final velocity is also v. but the velocity must decrease so D is incorrect.
Because the collision is inelastic, the final velocity will reduce.
In case of A, the change in momentum is below minimum change in momentum achievable, ie 2mv. so incorrect
In case of B, the change in momentum will be 2mv when final velocity is zero. However, ball rebonds with some velocity thus making B incorrect.
In case of C, the change in momentum will be 3mv when final velocity is v/2. This is reasonable thus correct.
In case of D, the change in momentum will be 4mv only when the final velocity is also v. but the velocity must decrease so D is incorrect.