CIE iGCSE Co-Ordinated Science P1.7 Pressure Exam Style Questions Paper 1
▶️ Answer/Explanation
The force applied on the pin is the same on both ends, but pressure depends on the area over which the force is applied. The sharp point of the pin has a very small area, so pressure on the cork is much higher than the pressure on the thumb (which has a larger area). This greater pressure allows the pin to penetrate the cork without causing injury to the thumb. Since pressure is inversely proportional to area, the smaller area of the pin tip creates a greater pressure, pushing it into the cork.
✅ Answer: (C)
✅ Answer: (C)
▶️ Answer/Explanation
Since all beakers are identical (same base area), the pressure on the bench depends only on the total weight of the beaker and liquid: \(P = \frac{F}{A} = \frac{mg}{A}\), where \(m = \rho \times V\).
Beaker A contains the largest volume of salt water (highest density), giving it the greatest mass and therefore the greatest weight and pressure on the bench.
✅ Answer: (A)
Beaker A contains the largest volume of salt water (highest density), giving it the greatest mass and therefore the greatest weight and pressure on the bench.
✅ Answer: (A)
▶️ Answer/Explanation
Pressure is calculated using \(P = \dfrac{F}{A}\), where \(F\) is the force (weight) and \(A\) is the contact area.
Decreasing the weight reduces the numerator, and increasing the base area increases the denominator.
Both changes together must reduce the overall pressure, since \(P\) decreases whenever \(F\) falls and \(A\) rises.
✅ Answer: (B)
Decreasing the weight reduces the numerator, and increasing the base area increases the denominator.
Both changes together must reduce the overall pressure, since \(P\) decreases whenever \(F\) falls and \(A\) rises.
✅ Answer: (B)
▶️ Answer/Explanation
Pressure is calculated using \( P = \dfrac{F}{A} \), where F is the force (the person’s weight) and A is the contact area.
Snowshoes spread the person’s weight over a much larger area of snow than a normal boot.
Since the force (weight) stays the same but the area increases, the pressure on the snow decreases.
✅ Answer: (A)
Snowshoes spread the person’s weight over a much larger area of snow than a normal boot.
Since the force (weight) stays the same but the area increases, the pressure on the snow decreases.
✅ Answer: (A)
Question
When driving cars on soft sand, drivers are advised to reduce the pressure of the air in the tyres. Why does this cause the cars to sink less into the sand?
A. The area of the tyres in contact with the sand is decreased.
B. The area of the tyres in contact with the sand is increased.
C. The downward force on the sand is decreased.
D. The downward force on the sand is increased.
▶️Answer/Explanation
Answer: B. The area of the tyres in contact with the sand is increased.
Explanation: Reducing tyre pressure increases the contact area between the tyres and the sand, distributing the car’s weight over a larger area and reducing the pressure on the sand, which prevents sinking.