Question

Why is it harder to lift a 100-pound sack of rice than to lift a 5-pound bag of sugar?

Answer 1

1 pound mass is equivalent to 0.454 kg mass

now the weight of the object of mass 1 pound will be

$W = mg = 0.454 \times 9.8 = 4.45 N$

now force required to pull upward a 100 pound sack will be given as

$F = 100 \times 4.45 = 445 N$

Also we can say that force required to pull a bag of 5 pound mass will be

$F = 5 \times 4.45 = 22.2 N$

so here we can see that 22.2 N force is very small as we compare it with 445 N this is the reason it is easy to pull 5 pound bag of sugar then 100 pound sack of rice