. A 2.0 kg brick has the dimensions 7.5 cm x 15 cm x 30 cm. Find the pressure exerted by the brick on a table when it is resting on its various faces.
pressure= mg/bottom area.
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To find the pressure exerted by the brick on the table when it is resting on its various faces, we need to use the formula for pressure:
Pressure = Force / Area
The force exerted by the brick on the table is equal to its weight. The weight of an object is given by:
Weight = mass x gravity
Where the gravity is approximately 9.8 m/s^2.
First, let's calculate the weight of the brick:
Weight = mass x gravity
Weight = 2.0 kg x 9.8 m/s^2
Weight = 19.6 N
Next, we need to find the area of each face of the brick. Since the brick has six faces, we will calculate the pressure for each face.
Face 1: The bottom face of the brick
The area of the bottom face is equal to the length times the width.
Area = length x width
Area = 15 cm x 30 cm
Area = 450 cm^2
Now, we can calculate the pressure on the table when the brick is resting on its bottom face:
Pressure = Force / Area
Pressure = 19.6 N / 450 cm^2
Note that the area needs to be converted from cm^2 to m^2 because the force is in newtons.
1 m^2 = 10,000 cm^2
Pressure = 19.6 N / (450 cm^2 / 10,000 cm^2/m^2)
Pressure = 19.6 N / 0.045 m^2
Pressure ≈ 435.56 Pa
The pressure exerted by the brick on the table when it is resting on its bottom face is approximately 435.56 Pa.
Similarly, you can calculate the pressure for the other faces of the brick using the same method.
To find the pressure exerted by the brick on a table, we need to use the formula:
Pressure = Force/Area
Since the brick is resting on its various faces, we need to calculate the pressure for each face separately.
First, we need to calculate the force exerted by the brick. The force can be calculated using the formula:
Force = mass * gravity
Given that the mass of the brick is 2.0 kg and the acceleration due to gravity is approximately 9.8 m/s², we can calculate the force:
Force = 2.0 kg * 9.8 m/s² = 19.6 N
Now, let's calculate the pressure for each face:
1. Bottom face:
The area of the bottom face is equal to its width multiplied by its length. So, the area is:
Area = 7.5 cm * 15 cm = 112.5 cm²
Since pressure is typically measured in pascals (Pa), we need to convert the area to square meters:
Area = 112.5 cm² ÷ (100 cm/m)² = 0.01125 m²
Now we can calculate the pressure on the bottom face:
Pressure (bottom face) = 19.6 N ÷ 0.01125 m² = 1742.2 Pa
2. Top face:
The pressure on the top face would be the same as the pressure on the bottom face since the weight acts downward and the reaction force of the table acts upward.
Pressure (top face) = 1742.2 Pa
3. Side faces:
The area of the side faces can be calculated by multiplying the height of the brick by the width of the brick. So, the area is:
Area = 15 cm * 30 cm = 450 cm²
Converting the area to square meters:
Area = 450 cm² ÷ (100 cm/m)² = 0.045 m²
Now we can calculate the pressure on the side faces:
Pressure (side faces) = 19.6 N ÷ 0.045 m² = 435.6 Pa
Therefore, the pressure exerted by the brick on the table when it is resting on its various faces is:
- On the bottom and top face: 1742.2 Pa
- On the side faces: 435.6 Pa