Question

A block is thrown with a velocity of 2 m/sec (relative to ground) on a belt, which is moving with velocity of 4 m/sec in opposite direction to the initial velocity of the block. If the block stops slipping on the belt after 4 seconds of the throwing then choose the correct statement/s

Answer 1

ANSWER

Let belt is moving towards left (4m/s) and initial velocity of block is towards right(2m/s).

Now let us assume everthing wrt belt velocity of block will be 6m/s towards right and final velocity will be zero.

So acceleration is 1.5m/s

2

because time taken to stop wrt belt is 4 sec.

Distance travelled wrt belt is S=6×4−

2

1

×1.5×4

2

=12

Distance travelled by belt in that time is 4×4=16

Now taking direction of movement of belt as positive we can say that

Option C. Displacement wrt to belt is -12m.

Option B. Displacement wrt ground is (-12+16=4)=4m.

Also displacement wrt ground will be zero when S=6×t−

2

1

×1.5×t

2

−4×t=0 =>t=

3

8

so option D is also correct.