Question

A wooden cube having mass 10 kg is dropped from the top of a building . After 1 s , a bullet of mass 20 g fired at it from the ground hits the block with a velocity of 1000 m/s at an angle of 30o to the horizontal moving upwards and gets imbedded in the block . The velocity of the block/bullet system immediately after the collision is: 17 m/s 27 m/s 52 m/s 10 m/s
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Answer 1

Answer:

Correct option is

B

40ms

−1

upward

Time after which collision takes place

t=

u

h

=

100

100

=1sec

Initial velocity of the wooden block

u

1

=gt=10×1=10m/s

Initial velocity of the bullet

u

2

=u−gt=100−10×1=90m/s

m

1

u

1

−m

2

u

2

=(m

1

+m

2

)V

∴V=−40m/s

Hence the velocity immediately after collision will equal to 40 m/s in the upward direction .