Which will exert more pressure, $100 \mathrm{kg}$ mass on $10 {\mathrm{m}}^2$ or $50 \mathrm{kg}$ mass $4 {\mathrm{m}}^2$? Give reason. (Take $g=10 \mathrm{m}/{\mathrm{s}}^2$)

When an object is immersed in a fluid, two forces act on the object in vertically opposite directions. Name them also write the factors on which the magnitude of these forces depends.

The density of turpentine at $293 \mathrm{K}$ is given as $870 \mathrm{kg} {\mathrm{m}}^{-3}$. Identify and write the name of the substances that sink in turpentine at the same temperature.

A student has to perform the experiment for comparing the pressure of the given cuboid placed at different faces. The steps given below are not in correct sequence:

$\left(i\right)$ To place the cuboid slowly on the sand and note the reading.

$\left(ii\right)$ To calculate the least count of spring balance.

$\left(iii\right)$ To measure the zero error in the spring balance.

$\left(iv\right)$ To measure the weight of the given cuboid.

The correct sequence of steps will be

In an experiment, Sudhir took a solid iron cuboid having mass $5 \mathrm{kg}$ and dimensions $30 \mathrm{cm}\times 20\mathrm{cm}\times 10 \mathrm{cm}$. He kept the cuboid on the table. The force and the pressure exerted by the cuboid on the table top if it lies with its face of dimensions $20 \mathrm{cm}\times 10 \mathrm{cm}$ respectively would be. (Take $g=9.8 \mathrm{m}/{\mathrm{s}}^2$ )