Question

1)calculate the thrust exerted by a block of mass 50g

2)find the pressure exerted by a cubical block of side 10cm and mass 400g when placed on a table top

3)a rectangular iron block of mass 10g and dimensions 20cm*10cm*5cm is placed on a table. find the pressure exerted by a block on the table if the block lies on the table with dimensions

I)20cm*10cm and ii)10cm*5cm

Answer 1

1. 50g= 0.05 kg
=》 thrust( perpendicular force) = ma
= 0.05× 10=0.5N

2. length = 10cm= 0.1m
mass = 400g= 0.4kg
P=F/A

=》 P= (0.4×10)/0.1
=4/0.1
=40Pa

3. i) mass= 10g= 0.01 kg
length= 20cm=0.2m
width= 10cm=0.1m
=》 area of base= 0.2×0.1
=0.02m^2

=》 P= F/A
=》 P= (0.01×10)/0.02
= 0.1×0.02
= 0.002Pa

ii)width= 10cm=0.1m
length= 5cm=0.05m

Area of base= 0.1×0.05= 0.005m^2
=》 P= 0.1/0.005 ( force is given in the previous part)
= 20Pa