Forces and Motion
A ball is dropped from rest and hits the ground after 1.5 s. Calculate the height of the drop to 2 d.p.
11.03m
A 5.0 kg mass is lifted 2.0 m. Calculate the increase in gravitational potential energy.
98J
What type of wave is depicted below?
Transverse
State Kirchhoff’s Current Law (KCL) and Kirchhoff’s Voltage Law (KVL).
Kirchhoff’s Current Law (KCL): At any junction in an electrical circuit, the total current flowing into the junction equals the total current flowing out of the junction. (Conservation of charge).
Kirchhoff’s Voltage Law (KVL): The sum of the potential differences (voltages) around any closed loop in a circuit is zero. (Conservation of energy).
Define half-life.
Half-life = time for half the nuclei in a radioactive sample to decay.
A car accelerates uniformly from rest at 3.0 m/s² for 6.0 s. Find its final velocity.
18.0 m/s
A 60 W light bulb runs for 2 hours. How much energy does it use in kJ?
432kJ
Light enters glass at 30° from air (n=1.5). Find the angle of refraction.
19.5 degrees
In a series circuit with three identical resistors, a student says the current splits evenly between them. Correct this misconception.
Current does not split in series, it is the same. Voltage divides.
A 16 g sample of a radioisotope with half-life 2 h decays. How much remains after 6 h?
2g
A 2.0 kg trolley moving at 4.0 m/s collides inelastically with a stationary 1.0 kg trolley. Find their final velocity.
2.67 m/s
A 2.0 kg ball moving at 6.0 m/s is brought to rest by friction over 3.0 m. Calculate the average friction force.
12N
A student claims red light bends more than blue light in glass. Is this correct? Explain.
The amount light bends depends on the refractive index of the material for that wavelength.
Glass has a higher refractive index for shorter wavelengths (like blue) than for longer wavelengths (like red).
Since blue light has a shorter wavelength, it travels more slowly in glass than red light.
Slower speed → greater change in direction → more bending towards the normal.
A 24 V supply powers a parallel circuit with two resistors: 12 Ω and 6 Ω. Find the total current drawn.
6.0A
A nucleus has a mass defect of 0.020 u. Calculate its binding energy in MeV (1 u=931.5 MeV)
18.6 MeV
A 1.2 kg soccer ball is initially at rest. A player kicks it, giving it a velocity of 18 m/s in 0.060 s. Calculate the average force applied to the ball.
360N (in direction of motion)
A 600 W kettle boils 1.0 L of water (specific heat 4200 J/kgK) from 20°C to 100°C. Assuming no losses, find the time taken.
9.3 minutes = 560 seconds
1A guitar string produces a note of 440 Hz. If the wave speed on the string is 330 m/s, calculate the wavelength.
0.75m
A 6.0 Ω resistor has 3.0 A flowing through it for 5.0 min. How much energy is dissipated?
16200J
Carbon-14 has a half-life of 5730 years. A fossil is found to contain 25% of its original C-14. Estimate its age.
11460 years
A 1200 kg car moving at 20 m/s collides with a stationary 800 kg car. After the collision, the two stick together. Calculate their final velocity and % KE loss.
12m/s and 40% KE lost
A rollercoaster car of 250 kg starts at 30 m height, speeds down a frictionless track, then encounters a section where 20% of its mechanical energy is lost to heat. What is its maximum speed afterwards?
21.6 m/s
A sonar signal returns from the ocean floor after 2.4 s. If sound travels at 1500 m/s, how deep is the ocean?
1800m
In a circuit, two resistors (4 Ω and 6 Ω) are in series across a 20 V supply. Use Kirchhoff’s laws to find the current and the potential drop across each resistor.
Current = 2.0 A, V₄ = 8 V, V₆ = 12 V
A nucleus with atomic mass 235.0439 u splits into fission fragments with combined mass 234.8590 u. Calculate the energy released per fission event in MeV.
172 MeV