IB Physics HL Paper 1 Question Bank

1.) When a skydiver opens her parachute, she is falling with terminal velocity. What is the direction of the velocity and acceleration vector before she reaches the new terminal speed?
A.) Velocity: Upwards, Acceleration: Upwards
B.) Velocity: Upwards, Acceleration: Downwards
C.) Velocity: Downwards, Acceleration: Upwards
D.) Velocity: Downwards, Acceleration: Downwards

Answer: C
Since the skydiver has opened their parachute, the motion of the skydiver is now slow and downwards. When an object slows down, its acceleration is always opposite to the direction of its motion. Since the diver is moving down, the direction and magnitude of the velocity vector is downwards. Since her speed is decreasing, the acceleration vector must point opposite to the velocity vector.

2.) A sports car is accelerated from 0 to 120 km per hour in 4 s. What is the acceleration of the car?
A.) 0.9 g
B.) 0.4 g
C.) 0.3 g
D.) 4 g

Answer: A
120 km/h needs to be converted to m/s first since the time is given in seconds. Therefore,
120 km/hr * (1000 m)/(1 km) * (60 min)/(1 hr) * (60 sec)/(1 min) = 33.333 m/s.
Acceleration is change in velocity/change in time, therefore:
(33.333 m/s – 0 m/s) /4 = 8.33325 m/s2
As the answer is given in g’s, we will divide the acceleration by g. 1 g = 9.8 m/s2. Therefore,
8.33325/9.8 = 0.8503 g’s which is approximately, 0.9 g’s

3.) In a flask, energy is transmitted to the water at a rate P. When the water approaches its boiling point, P is raised. What modifications have been made to the water’s temperature and rate of evaporation since the change?
A.) Temperature increases, Rate of Evaporation increases
B.) Temperature increases, Rate of Evaporation stays the same
C.) Temperature stays the same, Rate of Evaporation increases
D.) Temperature stays the same, Rate of Evaporation stays the same

Answer: C
There is no change in temperature after it reaches boiling point no matter how much the water is heated. However, the rate at which the energy is transmitted increases, therefore, the rate of evaporation also increases.

4.) Which of the follow statements are true about total internal energy and total intermolecular potential energy of a solid substance when it undergoes sublimation to become a gas?
A.) Internal energy increases, intermolecular potential energy stays the same
B.) Internal energy increases, intermolecular potential energy increases
C.) Internal energy stays the same, intermolecular potential energy stays the same
D.) Internal energy stays the same, intermolecular potential energy increases

Answer: B
The intermolecular potential energy increases because potential energy of any matter depends upon inter molecular space and gases have highest inter molecular space. Furthermore, if the potential energy increases, the internal energy is also bound to increase since the internal energy is the sum of the kinetic and potential energy.

5.) What is the phase difference between the displacement and acceleration of a particle executing simple harmonic motion (SHM)?
A.) π
B.) π/3
C.) 3π/4
D.) 0

Answer: A
Since y = Asinϕ and a=-ω2Asinϕ
-sinϕ=sin(ϕ+π)
So, acceleration is a heat of displacement a phase 𝜋

6.) There is a flow of charge through a liquid. 0.15 C of negative ions and 0.15 C of positive ions move facing each other. What is the magnitude of the electric current flowing through the liquid?
A.) 0.075
B.) 0
C.) 0.15
D.) 0.3

Answer: D
Since the charged ions have separate magnitudes and are facing each other, the electric current flowing through the liquid is the sum of both charges. This was because they are oppositely charged ions.

7.) A particle has a charge of ne. It is accelerated through a potential difference V. How is the work done of the particle calculated?
A.) neV
B.) ne/V
C.) V/ne
D.) eV/n

Answer: A
Work done is calculated by multiplying the charge with the potential difference. Therefore, the work done of the particle is calculated by ne x V

8.) A proton traveling at velocity v enters a magnetic and electric field. There is no proton deflection. With a velocity of v, an electron and an alpha particle enter the same space. Which of the following statements are true with regards to the alpha and electron’s paths?
A.) Path of electron is not deflected, path of alpha particle is not deflected
B.) Path of electron is deflected, path of alpha particle is not deflected
C.) Path of electron is deflected, path of alpha particle is deflected
D.) Path of electron is not deflected, path of alpha particle is deflected

Answer: A
Neither alpha-particle will be deflected nor electron will be deflected because net force on both particles will be zero.

9.) If a particle with an atomic number Z undergoes a beta-plus (β+) decay, what is the atomic number of the nuclide produced and the other particle emitted?
A.) Atomic number (Z-1), Other particle is neutrino
B.) Atomic number (Z-1), Other particle is antineutrino
C.) Atomic number (Z+1), Other particle is neutrino
D.) Atomic number (Z+1), Other particle is antineutrino

Answer: A
In a beta plus (β+) decay, a proton is converted to a neutron and the process creates a positron and an electron neutrino. β+decay is also known as positron emission.

10.) A beaker has 2 kg of water at room temperature. It is heated on a 450 W hot plate. The specific heat capacity of water is 4200 J kg-1 K-1. When the temperature of the water reaches a constant value, it is removed from the hot plate. What is the initial rate of change of temperature?
A.) 0.005 Ks-1
B.) 0.5 Ks-1
C.) 0.05 Ks-1
D.) 5 Ks-1

Answer: D
The formula for specific heat capacity is Q = mcΔT. We have Q (power), mass and specific heat capacity. The equation needs to be rearranged to make ΔT the subject of the equation. Therefore, it is ΔT = Q/mc. Substituting the values, we have 450/(4200*2) = 0.05357 Ks-1

11.) After a metallic surface is exposed to infrared radiation, photoelectrons are released from the same surface. The ultraviolet radiation has the same intensity as the infrared radiation. What will happen to the photoelectrons’ kinetic energy and the pace at which they are ejected?
A.) Photoelectrons kinetic energy increases and rate at which they are ejected is constant
B.) Photoelectrons kinetic energy increases and rate at which they are ejected increases
C.) Photoelectrons kinetic energy is constant and rate at which they are ejected increases
D.) Photoelectrons kinetic energy is constant and rate at which they are ejected is constant

Answer: B
Since ultraviolet radiation has a higher frequency than infrared radiation, the kinetic energy of the photoelectrons increases. Ultraviolet radiation also has shorter waves and thus oscillates more rapidly and carries more energy per photon. Since the kinetic energy increases, the rate at which they are ejected also increases.

12.) During gamma decay, photons of discrete energy are emitted. What does this mean?
A.) Quantum tunneling
B.) Pair Production
C.) Nuclear energy levels
D.) Atomic energy levels
Answer: C
During gamma decay, an excited nucleus emits a particle therefore showing the existence of nuclear energy levels.