Answer:
Explanation:
Let the initial velocity of small block be v .
by applying conservation of momentum we can find velocity of common mass
25 v = 75 V , V is velocity of common mass after collision.
V = v / 3
For reaching the height we shall apply conservation of mechanical energy
1/2 m v² = mgh
1/2 x 75 x V² = 75 x g x 10
V² = 2g x 10
v² / 9 = 2 x 9.8 x 10
v² = 9 x 2 x 9.8 x 10
v = 42 m /s
small block must have velocity of 42 m /s .
Impulse by small block on large block
= change in momentum of large block
= 75 x V
= 75 x 42 / 3
= 1050 Ns.
The average speed would be 0.65 m/s, therefore the correct option is (A).
The average speed is calculated by the formula
Average speed= (total distance/ total time)
The total distance of the trip=9.5+3.5+15=28 m
The total time of trip=43 sec
Therefore the average speed=28/43=0.65 m/s.
