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CBSE Class 9 Answered

Asked by ayan1.chatterjee | 14 Jan, 2021, 03:30: PM
answered-by-expert Expert Answer
Figure shows the forces acting on each block.
 
For the block that is hanging vertically, weight (10g) is acting downward and Tension force in the string is acting upward.
 
If the block is getting acceleration a in downward direction , then we have by Newton's second law
 
10g - T = 10 a  ........................(1)
 
For the block moving along inclined surface, Tension force T is pulling the block upwads along the inclined surface ,
while the component of weight parallel to inclined surface (10g) sin30 is acting in opposite direction of movement.
 
Hence if the block moves with acceleration a , By Newton's second law , we have
 
T - (10g) sin30 = 10 a  ...................(2)
 
By adding eqn.(1) and (2) , w e get ,  ( 20 a ) = (10g) [ 1 - sin30 ] = 5 × 10 
 
( we have assumed g = 10 m/s2 in above equation )
 
Hence , acceleration  a = 50/20 = 2.5 m/s2
Answered by Thiyagarajan K | 14 Jan, 2021, 05:05: PM

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