Question

# 4. A block of copper of density 8.9 g/cm² measures 5 cm x 3 cm x 2 cm. Given that the force of gravity is 10 Nkg !, determine: (a) the maximum pressure. (b) the minimum pressure that it can exert on a horizontal surface

Answer

(a) The maximum pressure is 4450 N/m². (b) The minimum pressure is 1780 N/m². Explanation: To calculate the pressure, we first need to find the force acting on the small area. By using the formula force = mass x gravity, we calculate the force to be 2.67 N. Next, we need to find the area by converting 3cm x 2cm into m²: 6cm² = 0.0006 m². Therefore, the pressure is calculated by dividing the force by the area: 2.67N/0.0006m² = 4450N/m². To find the minimum pressure, we need to use the same formula with the larger area. We convert 5cm x 3cm into m²: 15cm² = 0.0015m². The force acting on the larger area is still 2.67 N, so the minimum pressure is calculated as 2.67N/0.0015m² = 1780N/m².