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 used to calculate pressure?

• Pressure = Area / Force

• Pressure = Force x Area

• Pressure = Force / Area

• Pressure = Force + Area

What is the initial pressure when the force is 70 newtons and the area is 20 cm²?

• 3.5

• 2.5

• 4.0

• 3.0

After increasing the force by 10 newtons and the area by 10 cm², what is the new pressure?

• 3.5

• 2.67

• 2.5

• 3.0

How much does the pressure decrease when comparing the initial and new pressures?

• 1/2

• 2/3

• 1

• 5/6

Did the pressure decrease by less than 20% as Helen claimed?

• Yes, it decreased by exactly 20%

• No, it decreased by more than 20%

• No, it decreased by exactly 20%

• Yes, it decreased by less than 20%