Question

A block of wood is kept on a tabletop. The mass of wooden block is 5 kg and its dimensions are 40 cm × 20 cm × 10 cm.
Find the pressure exerted.​

Answer 1

Explanation:

Mass of the wooden block, m=5kg

Thrust due to wooden block,

Mg=5kg×9.8ms

−2

=49N

(a) Surface area of 20cm×10cm surface,

A=(20×10)cm

2

=(0.2×0.1)m

2

=0.02m

2

P=

A

mg

P=

0.02m

2

49N

=

0.02

49

Nm

−2

or Pressure, P=2450Nm

−2

.

(b) Surface area of 40cm×20cm surface,

A=(40×20)cm

2

=(0.4×0.2)m

2

=0.08m

2

P=

0.08m

2

49N

=

0.08

49

Nm

−2

or Pressure, P=612.5Nm

−2

Answer 2

Answer:

Pressure = mass / volume

                = 5kg / 40 cm × 20 cm × 10 cm

                = 5 kg / 8000 cm³

                = 0.000625 kg / cm³

                = 0.625 × 10³ Pascal