a rectangular piece of wood measuring 20cm by5cm by3cm weighs 900kg.find the greatest pressure the piece of wood can exert if placed on a table
That little piece of wood does NOT weigh 900 kg (maybe your car does)
I think you mean 0.900 kg or 900 grams
make its contact with the table as small as possible while not tipping over (standing on end)
so area touching table is
.05 * .03 = .0015 m^2
so
p = force/area = 0.9/.0015 = 600 Pascals
need weight/area, not mass /area
600 * 9.81 = 5886 Pascals
To find the greatest pressure the piece of wood can exert when placed on a table, we need to calculate the pressure exerted by the weight of the wood on the table surface.
Pressure is defined as force divided by area. Therefore, we need to calculate the force exerted by the weight of the wood and divide it by the surface area in contact with the table.
First, let's calculate the volume of the wood:
Volume = length × width × height
= 20 cm × 5 cm × 3 cm
= 300 cm³
Next, we need to convert the volume to liters (since 1 liter is equal to 1 cubic decimeter or 1000 cm³).
Volume = 300 cm³ / 1000
= 0.3 liters
Now let's convert the given weight of the wood from kilograms to grams:
Weight = 900 kg × 1000 g/kg
= 900000 g
Since the weight of the wood is equal to the force exerted on the table, we can now calculate the pressure:
Pressure = Force / Area
To find the area in contact with the table, we need to determine the dimensions of the wood that are in contact with the table. Since the wood is rectangular, the area in contact is the product of the length and width, which is:
Area = length × width
= 20 cm × 5 cm
= 100 cm²
Now, we can calculate the pressure:
Pressure = Weight / Area
= 900000 g / 100 cm²
= 9000 g/cm²
Therefore, the greatest pressure the piece of wood can exert if placed on a table is 9000 grams per square centimeter (g/cm²).