Answer to Question #288308 in Classical Mechanics for Dom

Question

a grain retailer puts a 1000 kg lead block under the platform of this scale. by how much does this increase the reading of the scale when 50kg sack of rice is on top of its platform, if the distance between their centers are .03 meter apart

Answer 1

Solution

Mass of lead block m=1000kg

Mass of sack rice m'=50kg

Distance between them d=0.3m

We know the gravitational force between them

$F=\frac{Gmm'}{d^2}$

Putting all values

$F=\frac{6.67\times10^{-11}\times1000\times50}{(0.3)^2}\\=3.7mN$

Now reading or change in mass is given by

$\Delta m=\frac{F}{g}\\=0.38g$