Q.

An object of mass 100 kg falls from point A to B as shown in figure. The change in its weight corrected to the nearest integer is (RE is the radius of the Earth)    [2024]

1 49 N  
2 89 N  
3 5 N  
4 10 N  

Ans.

(1)

Given, m=100kg,g=10m/s2

WA=mgA=mg(RERE+HB)2=mg(RERE+2RE)2=mg9

WB=mgB=mg(RERE+HB)2=mg(RERE+3RE2)2=4mg25

Change in weight =WB-WA

=4mg25-mg9=36mg-25mg225

=11mg225=11225×100×10=49 N