Question

An iron block of dimensions 5 cm X 10 cm X 15 cm has to be pushed along the floor. The force required will

be minimum when the surface in contact with ground is

A. (10 cm X 15 cm) surface B. (5 cm X 15 cm) surface

C. (10 cm X 5 cm) surface D. force is same for all surfaces

Answer 1

HOLA!!

HERE YOUR ANSWER IS

C) (10cm×5cm) surface.

REASON:

we know that pressure = force /area

then force = pressure × area

this shows that force is directly proportional to area.

now 10cm ×15 cm = 150cm^-2

5 cm×15 cm = 75 cm^-2

10cm × 5cm = 50cm^-2

we need minimum force so we should choose surface with minimum area that is (10cm×5cm).

HOPE MY ANSWER HELPS YOU!!

Answer 2

The answer is C as C has the smallest surface area.Thus,frictional force is smallest,less force is needed to move the iron block is minimum