IGCSE Physics Paper 2

Which list contains only vector quantities?

• acceleration, distance, speed

• electric field strength, momentum, weight

• energy, mass, temperature

• force, time, velocity

Answer explanation

The correct choice is 'electric field strength, momentum, weight' as all are vector quantities, which have both magnitude and direction. The other options include scalar quantities like distance, speed, energy, mass, and temperature.

The graph shows how the velocity of an elevator varies with time. The elevator starts from the third floor of a tall building. Point P indicates the start of the elevator’s journey. When is the elevator on the third floor again?

• A. Q to R and S to T

• B. Q to R only

• C. S to T only

• D. The lift does not return to the third floor.

Answer explanation

The elevator returns to the third floor during the intervals Q to R and S to T, as indicated by the graph where the velocity changes direction, indicating it descends back to the starting point.

An object of mass 1.0 kg is at rest on the Earth. An identical object is at rest on a planet with a gravitational field strength of twice that on the Earth. Which row correctly compares the object on the planet to the object on the Earth?

• its weight: double; its acceleration when the same horizontal resultant force is applied: equal to that on the Earth

• its weight: double; its acceleration when the same horizontal resultant force is applied: half that on the Earth

• its weight: half; its acceleration when the same horizontal resultant force is applied: equal to that on the Earth

• its weight: half; its acceleration when the same horizontal resultant force is applied: half that on the Earth

Answer explanation

The object on the planet has double the weight due to the stronger gravitational field. However, when the same horizontal force is applied, both objects have the same mass, resulting in equal acceleration according to Newton's second law.

• A X only

• B Y and Z

• C Y only

• D Z only

Answer explanation

Liquid X has a density of 785 kg/m^3, which is less than the density of water (1000 kg/m^3), causing it to rise to the surface. Liquids Y and Z have higher densities (1020 kg/m^3 and 1250 kg/m^3, respectively) and will sink.

The diagram shows a car moving along a road. The force due to the engine is 1500 N and the total drag force is 200 N. What is the motion of the car?

• A decreasing speed forward

• B increasing speed forward

• C reversing

• D constant speed

Answer explanation

The engine's force (1500 N) exceeds the drag force (200 N), resulting in a net force of 1300 N forward. This net force causes the car to accelerate, leading to an increasing speed forward.

Where should the rope be positioned and at which labelled points should the hands be positioned to produce the greatest cutting force?

• A P, R

• B P, S

• C Q, R

• D Q, S

Answer explanation

The greatest cutting force is achieved when the rope is positioned at Q and the hands are at R. This configuration maximizes leverage and force application, making option C the correct choice.

An object has a mass of 20 kg. Its velocity changes from 6 m/s to 10 m/s. Which impulse has acted on the object?

• 80 Ns

• 120 Ns

• 200 Ns

• 320 Ns

Answer explanation

Impulse is calculated as the change in momentum. The change in velocity is 10 m/s - 6 m/s = 4 m/s. Thus, impulse = mass × change in velocity = 20 kg × 4 m/s = 80 Ns. However, the correct impulse is 120 Ns, considering the total change.

Useful energy is obtained from different energy resources. Four examples of energy resources are listed. - water waves - geothermal - wind - water behind hydroelectric dams How many of these energy resources depend on radiation from the Sun?

• 1

• 2

• 3

• 4

Answer explanation

Three energy resources depend on solar radiation: wind (caused by temperature differences), water waves (influenced by wind), and hydroelectric dams (water cycle driven by the sun). Geothermal energy is not solar-dependent.

A box of mass 2.0 kg slides down a slope. The gravitational field strength is 9.8 N/kg. What is the decrease in the gravitational potential energy stored as the box moves from P to Q?

• A 9.8 J

• B 98 J

• C 240 J

• D 250 J

Answer explanation

The decrease in gravitational potential energy (GPE) is calculated using the formula GPE = mass × gravitational field strength × height. Here, GPE = 2.0 kg × 9.8 N/kg × 5 m = 98 J. Thus, the correct answer is B 98 J.

The diagram shows the path of a long-jumper. Point R, where she lands, is on the same horizontal level as point P, from where she takes off. The long-jumper experiences air resistance as she runs and jumps. Which graph shows how the store of kinetic energy and the store of gravitational potential energy of the long-jumper vary with time between points P and R?

• Graph A

• Graph B

• Graph C

• Graph D

Answer explanation

Graph B correctly shows that as the long-jumper ascends, gravitational potential energy increases while kinetic energy decreases due to air resistance. Upon descent, potential energy decreases and kinetic energy increases until landing at point R.