GCSE Secondary Maths Age 13-17 - Ratio, Proportion & Rates of Change: Speed, Density & Pressure - Explained

The video tutorial explains a physics problem involving pressure calculation. Initially, a force of 70 newtons is applied over an area of 20 cm². The force and area are both increased by 10 units, and the new pressure is calculated. The tutorial evaluates Helen's claim that the pressure decreases by less than 20%. By calculating the initial and new pressures, the tutorial demonstrates that the pressure decreases by more than 20%, proving Helen incorrect. The video also outlines the marks distribution for solving the problem.

What is the formula for calculating pressure?

Calculate the original pressure when the force is 70 newtons and the area is 20 centimeters squared.

What is the new pressure after increasing the force by 10 newtons and the area by 10 centimeters squared?

How much did the pressure decrease after the changes were made?

Explain why Helen's statement about the pressure decrease being less than 20% is incorrect.